Search Results

Search found 690 results on 28 pages for 'routers'.

Page 25/28 | < Previous Page | 21 22 23 24 25 26 27 28  | Next Page >

  • What are the possible tags inside the "global" tag in Magento "config.xml" file?

    - by Knowledge Craving
    Can someone professional experienced Magento developer tell me how to accomplish the following in Magento? I want to know what are the possible tags that can fit in the "global" tag of the "config.xml" page of every module's etc folder? I have tried searching for this answer at many places in Internet but in vain. Please provide the full details along with it for Magento version = 1.4.0.0, because I want at least the users accessing this website find it useful enough, instead of scratching their heads. I really want a detailed explanation, because every newbie like me gets totally confused at this point. From what I know till now, is that in this page, you can set routers, rewrites, cron jobs, admin html, front-end html and many more. But without any strong concepts, none can go ahead with the belief that his code is 100% correct w.r.t. the Magento MVC architecture. So please I want that strong fundamental concept, getting underlined here, with a detailed explanation about it, so that no one gets into this pitfall ever again. Many many thanks to those who can answer only upon knowing the total concept clearly.

    Read the article

  • Trying to move files with specific file names from root directory to a subfolder

    - by Justin Reagan
    Hi I'm still pretty new to powershell so I apologize if I ask something that extremely basic. I have a root directory on a tftp server that pulls down config files from routers and other equipment every night. The files are like this IPaddress_YYYYMMDD_TA5000. There is a limitation in the equipment where the files can't be set to move into the root directory on their own. What I want to do is make a powershell script that will only move the files with the TA5000 part in the filename to the sub directory and only keep the 5 most recent files. I looked but I couldn't seem to find what I would need to do to parse the file for that specific string. I already have the portion of the script to delete the files based on age that was simple. Any help on getting started would be appreciated. Edit: I forgot to post the code I was trying. Move-Item c:\tftptransferfiles c:\tftptransferfiles\sca | Where-Object {_.name -like "*TA5000*"} I keep getting a error saying that the item at C:\tftptransferfiles is in use.

    Read the article

  • So No TECH job so far.

    - by Ratman21
    O I found some temp work for the US Census and I have managed to keep the house (so far) but, it looks like I/we are going to have to do a short sale and the temp job will be ending soon.   On top of that it looks like the unemployment fund for me is drying up. I will have about one month left after the Census job is done. I am now down to Appling for work at the KFC.   This is type a work I started with, before I was a tech geek and really I didn’t think I would be doing this kind of work in my later years but, I have a wife and kid. So I got to suck it up and do it.   Oh and here is my new resume…go ahead I know you want to tare it up. I really don’t care any more.   Scott L. Newman 45219 Dutton Way, Callahan, FL32011 H: (904)879-4880 C: (352)356-0945 E: [email protected] Web:  http://beingscottnewman.webs.com/                                                       ______                                                                                 OBJECTIVE To obtain a Network or Technical support position     KEYWORD SUMMARY CompTIA A+, Network+, and Security+ Certified., Network Operation, Technical Support, Client/Vendor Relations, Networking/Administration, Cisco Routers/Switches, Helpdesk, Microsoft Office Suite, Website Design/Dev./Management, Frame Relay, ISDN, Windows NT/98/XP, Visio, Inventory Management, CICS, Programming, COBOL IV, Assembler, RPG   QUALIFICATIONS SUMMARY Twenty years’ experience in computer operations, technical support, and technical writing. Also have two and half years’ experience in internet / intranet operations.   PROFESSIONAL EXPERIENCE October 2009 – Present*   Volunteer Web site and PC technician – Part time       True Faith Christian Fellowship Church – Callahan, FL, Project: Create and maintain web site for Church to give it a worldwide exposure Aug 2008 – September 2009:* Volunteer Church sound and video technician – Part time      Thomas Creek Baptist Church – Callahan, FL   *Note Jobs were for the learning and/or keeping updated on skills, while looking for a tech job and training for new skills.   February 2005 to October 2008: Client Server Dev/Analyst I, Fidelity National Information Services, Jacksonville, FL (FNIS acquired Certegy in 2005 and out of 20 personal, was one of three kept on.) August 2003 to February 2005: Senior NetOps Operator, Certegy, St.Pete, Fl. (August 2003, Certegy terminated contract with EDS and out of 40 personal, was one of six kept on.) Projects: Creation and update of listing and placement for all raised floor equipment at St.Pete site. Listing was made up of, floor plan of the raised floor and equipment racks diagrams showing the placement of all devices using Visio. This was cross-referenced with an inventory excel document showing what dept was responsible for each device. Sole creator of Network operation and Server Operation procedures guide (NetOps Guide).  Expertise: Resolving circuit and/or router issues or assist circuit carrier in resolving issue from the company Network Operation Center (NOC). As well as resolving application problems or assist application support in resolution of it.     July 1999 to August 2003: Senior NetOps Operator,EDS (Certegy Account), St.Pete, FL Same expertise and on going projects as listed above for FNIS/Certegy. (Equifax outsourced the NetOps dept. to EDS in 1999)         January 1991 to July 1999: NetOps/Tandem Operator, Equifax, St.Pete & Tampa, FL Same as all of the above for FNIS/Certegy/EDS except for circuit and router issues   EDUCATION ? New Horizons Computer Learning Center, Jacksonville, Florida - CompTIA A+, Security+, and     Network+ Certified.                        Currently working on CCNA Certification 07/30/10 ? Mott Community College, Flint, Michigan – Associates Degree - Data Processing and General Education ? Currently studying Japanese

    Read the article

  • OSI Model

    - by kaleidoscope
    The Open System Interconnection Reference Model (OSI Reference Model or OSI Model) is an abstract description for layered communications and computer network protocol design. In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data Link, and Physical Layers. It is therefore often referred to as the OSI Seven Layer Model. A layer is a collection of conceptually similar functions that provide services to the layer above it and receives service from the layer below it. Description of OSI layers: Layer 1: Physical Layer ·         Defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium. ·         Establishment and termination of a connection to a communications medium. ·         Participation in the process whereby the communication resources are effectively shared among multiple users. ·         Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel. Layer 2: Data Link Layer ·         Provides the functional and procedural means to transfer data between network entities. ·         Detect and possibly correct errors that may occur in the Physical Layer. The error check is performed using Frame Check Sequence (FCS). ·         Addresses is then sought to see if it needs to process the rest of the frame itself or whether to pass it on to another host. ·         The Layer is divided into two sub layers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. ·         MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. ·         LLC layer controls frame synchronization, flow control and error checking.   Layer 3: Network Layer ·         Provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks. ·         Performs network routing functions, and might also perform fragmentation and reassembly, and report delivery errors. ·         Network Layer Routers operate at this layer—sending data throughout the extended network and making the Internet possible.   Layer 4: Transport Layer ·         Provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers. ·         Controls the reliability of a given link through flow control, segmentation/de-segmentation, and error control. ·         Transport Layer can keep track of the segments and retransmit those that fail. Layer 5: Session Layer ·         Controls the dialogues (connections) between computers. ·         Establishes, manages and terminates the connections between the local and remote application. ·         Provides for full-duplex, half-duplex, or simplex operation, and establishes checkpointing, adjournment, termination, and restart procedures. ·         Implemented explicitly in application environments that use remote procedure calls. Layer 6: Presentation Layer ·         Establishes a context between Application Layer entities, in which the higher-layer entities can use different syntax and semantics, as long as the presentation service understands both and the mapping between them. The presentation service data units are then encapsulated into Session Protocol data units, and moved down the stack. ·         Provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa. The presentation layer works to transform data into the form that the application layer can accept. This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems. It is sometimes called the syntax layer. Layer 7: Application Layer ·         This layer interacts with software applications that implement a communicating component. ·         Identifies communication partners, determines resource availability, and synchronizes communication. o       When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. o       When determining resource availability, the application layer must decide whether sufficient network or the requested communication exists. o       In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer. Technorati Tags: Kunal,OSI,Networking

    Read the article

  • 5 Ways to Determine Mobile Location

    - by David Dorf
    In my previous post, I mentioned the importance of determining the location of a consumer using their mobile phone.  Retailers can track anonymous mobile phones to determine traffic patterns both inside and outside their stores.  And with consumers' permission, retailers can send location-aware offers to mobile phones; for example, a coupon for cereal as you walk down that aisle.  When paying with Square, your location is matched with the transaction.  So there are lots of reasons for retailers to want to know the location of their customers.  But how is it done? I thought I'd dive a little deeper on that topic and consider the approaches to determining location. 1. Tower Triangulation By comparing the relative signal strength from multiple antenna towers, a general location of a phone can be roughly determined to an accuracy of 200-1000 meters.  The more towers involved, the more accurate the location. 2. GPS Using Global Positioning Satellites is more accurate than using cell towers, but it takes longer to find the satellites, it uses more battery, and it won't well indoors.  For geo-fencing applications, like those provided by Placecast and Digby, cell towers are often used to determine if the consumer is nearing a "fence" then switches to GPS to determine the actual crossing of the fence. 3. WiFi Triangulation WiFi triangulation is usually more accurate than using towers just because there are so many more WiFi access points (i.e. radios in routers) around. The position of each WiFi AP needs to be recorded in a database and used in the calculations, which is what Skyhook has been doing since 2008.  Another advantage to this method is that works well indoors, although it usually requires additional WiFi beacons to get the accuracy down to 5-10 meters.  Companies like ZuluTime, Aisle411, and PointInside have been perfecting this approach for retailers like Meijer, Walgreens, and HomeDepot. Keep in mind that a mobile phone doesn't have to connect to the WiFi network in order for it to be located.  The WiFi radio in the phone only needs to be on.  Even when not connected, WiFi radios talk to each other to prepare for a possible connection. 4. Hybrid Approaches Naturally the most accurate approach is to combine the approaches described above.  The more available data points, the greater the accuracy.  Companies like ShopKick like to add in acoustic triangulation using the phone's microphone, and NearBuy can use video analytics to increase accuracy. 5. Magnetic Fields The latest approach, and this one is really new, takes a page from the animal kingdom.  As you've probably learned from guys like Marlin Perkins, some animals use the Earth's magnetic fields to navigate.  By recording magnetic variations within a store, then matching those readings with ones from a consumer's phone, location can be accurately determined.  At least that's the approach IndoorAtlas is taking, and the science seems to bear out.  It works well indoors, and doesn't require retailers to purchase any additional hardware.  Keep an eye on this one.

    Read the article

  • Type of computer for a developer on the road

    - by nabucosound
    Hi developers: I am planning to be traveling through eurasia and asia (russia, china, korea, japan, south east asia...) for a while and, although there are plenty of marvelous things to see and to do, I must keep on working :(. I am a python developer, dedicated mainly to web projects. I use django, sqlite3, browsers, and ocassionaly (only if I have no choice) I install postgres, mysql, apache or any other servers commonly used in the internets. I do my coding on vim, use ssh to connect, lftp to transfer files, IRC, grep/ack... So I spend most of my time in the terminal shells. But I also use IM or Skype to communicate with my clients and peers, as well as some other software (that after all is not mandatory for my day-to-day work). I currently work with a Macbook Pro (3 years old now) and so far I am very happy with the performance. But I don't want to carry it if I am going to be "on transit" for long time, it is simply huge and heavy for what I am planning to load in my rather small backpack (while traveling, less is more, you know). So here I am reading all kind of opinions about netbooks, because at first sight this is the kind of computer I thought I had to choose. I am going to use Linux for it, Microsoft is not my cup of tea and Mac is not available for them, unless I were to buy a Macbook air, something that I won't do because if I am robbed or rain/dust/truck loaders break it I would burst in tears. I am concerned about wifi performance and connectivity, I am going to use one of those linux distros/tools to hack/test on "open" networks (if you know what I mean) in case I am not in a place with real free wifi access and I find myself in an emergency. CPU speed should be acceptable, but since I don't plan to run Photoshop or expensive IDEs, I guess most of the time I won't be overloading the machine. Apart from this, maybe (surely) I am missing other features to consider. With that said (sorry about the length) here it comes my question, raised from a deep ignorance regarding the wars betweeb betbooks vs notebooks (I assume tablet PCs are not for programming yet): If I buy a netbook will I have to throw it away after 1 month on the road and buy a notebook? Or will I be OK? Thanks! Hector Update I have received great feedback so far! I would like to insist on the fact that I will be traveling through many different countries and scenarios. I am sure that while in Japan I will be more than fine with anything related to technology, connectivity, etc. But consider that I will be, for example, on a train through Russia (transsiberian) and will cross Mongolia as well. I will stay in friends' places sometimes, but most of the time I will have to work from hostel rooms, trains, buses, beaches (hey this last one doesn't sound too bad hehe!). I think some of your answers guys seem to focus on the geek part but loose the point of this "on the road" fact. I am very aware and agree that netbooks suck compared to notebooks, but what I am trying to do here is to find a balance and discover your experiences with netbooks to see first hand if a netbook will be a fail in the mid-long term of the trip for my purposes. So I have resumed the main concepts expressed here on this small list, in no particular order: keyboard/touchpad feel: I use vim so no need of moving mouse pointers that much, unless I am browsing the web, but intensive use of keyboard screen real state: again, terminal work for most of the time battery life: I think something very important weight/size: also very important looks not worth stealing it, don't give a shit if it is lost/stolen/broken: this may depend on kind of person, your economy, etc. Also to prevent losing work, I will upload EVERYTHING to the cloud whenever I'll have a chance. wifi: don't want to discover my wifi is one of those that cannot deal with half the routers on this planet or has poor connectivity. Thanks again for your answers and comments!

    Read the article

  • Randomely loosing wireless connexion with Cubuntu 12.04

    - by statquant
    I am presently experiencing random disconnections from my wireless network. It looks like it is more and more frequent (however I have not seen any clear pattern). This is killing me... Here is some information that should help (from ubuntu forums). Thanks for reading Machine : Acer Aspire S3 statquant@euclide:~$ lsb_release -d Description: Ubuntu 12.04.1 LTS statquant@euclide:~$ uname -mr 3.2.0-33-generic x86_64 statquant@euclide:~$ sudo /etc/init.d/networking restart * Running /etc/init.d/networking restart is deprecated because it may not enable again some interfaces * Reconfiguring network interfaces... statquant@euclide:~$ lspci 02:00.0 Network controller: Atheros Communications Inc. AR9485 Wireless Network Adapter (rev 01) statquant@euclide:~$ lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 004: ID 064e:c321 Suyin Corp. Bus 002 Device 003: ID 0bda:0129 Realtek Semiconductor Corp. statquant@euclide:~$ ifconfig wlan0 Link encap:Ethernet HWaddr 74:de:2b:dd:c4:78 inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::76de:2bff:fedd:c478/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:913 errors:0 dropped:0 overruns:0 frame:0 TX packets:802 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:873218 (873.2 KB) TX bytes:125826 (125.8 KB) statquant@euclide:~$ iwconfig wlan0 IEEE 802.11bgn ESSID:"Bbox-D646D1" Mode:Managed Frequency:2.437 GHz Access Point: 00:19:70:80:01:6C Bit Rate=65 Mb/s Tx-Power=16 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:on Link Quality=56/70 Signal level=-54 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:71 Missed beacon:0 statquant@euclide:~$ dmesg | grep "wlan" [ 17.495866] ADDRCONF(NETDEV_UP): wlan0: link is not ready [ 17.498950] ADDRCONF(NETDEV_UP): wlan0: link is not ready [ 20.072015] wlan0: authenticate with 00:19:70:80:01:6c (try 1) [ 20.269853] wlan0: authenticate with 00:19:70:80:01:6c (try 2) [ 20.272386] wlan0: authenticated [ 20.298682] wlan0: associate with 00:19:70:80:01:6c (try 1) [ 20.302321] wlan0: RX AssocResp from 00:19:70:80:01:6c (capab=0x431 status=0 aid=1) [ 20.302325] wlan0: associated [ 20.307307] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready [ 30.402292] wlan0: no IPv6 routers present statquant@euclide:~$ sudo lshw -C network [sudo] password for statquant: *-network description: Wireless interface product: AR9485 Wireless Network Adapter vendor: Atheros Communications Inc. physical id: 0 bus info: pci@0000:02:00.0 logical name: wlan0 version: 01 serial: 74:de:2b:dd:c4:78 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless configuration: broadcast=yes driver=ath9k driverversion=3.2.0-33-generic firmware=N/A ip=192.168.1.3 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn resources: irq:17 memory:c0400000-c047ffff memory:afb00000-afb0ffff statquant@euclide:~$ iwlist scan wlan0 Scan completed : Cell 01 - Address: 00:19:70:80:01:6C Channel:6 Frequency:2.437 GHz (Channel 6) Quality=56/70 Signal level=-54 dBm Encryption key:on ESSID:"Bbox-D646D1" Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 9 Mb/s; 12 Mb/s; 18 Mb/s Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s Mode:Master Extra:tsf=000000125fb152bb Extra: Last beacon: 40020ms ago IE: Unknown: 000B42626F782D443634364431 IE: Unknown: 010882848B960C121824 IE: Unknown: 030106 IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: Unknown: 2A0100 IE: Unknown: 32043048606C IE: Unknown: DD180050F2020101820003A4000027A4000042435E0062322F00 IE: Unknown: 2D1A4C101BFF00000000000000000000000000000000000000000000 IE: Unknown: 3D1606080800000000000000000000000000000000000000 IE: Unknown: DD0900037F01010000FF7F IE: Unknown: DD0A00037F04010000000000 And... finally, please note that I did the following (after looking for fixes of similar problems), but unfortunately it did not work sudo modprobe -r iwlwifi sudo modprobe iwlwifi 11n_disable=1

    Read the article

  • MySQL Server 5.6 defaults changes

    - by user12626240
    We're improving the MySQL Server defaults, as announced by Tomas Ulin at MySQL Connect. Here's what we're changing:  Setting  Old  New  Notes back_log  50  50 + ( max_connections / 5 ) capped at 900 binlog_checksum  off  CRC32  New variable in 5.6 binlog_row_event_max_size  1k  8k flush_time  1800  Windows changes from 1800 to 0  Was already 0 on other platforms host_cache_size  128  128 + 1 for each of the first 500 max_connections + 1 for every 20 max_connections over 500, capped at 2000  New variable in 5.6 innodb_autoextend_increment  8  64  Now affects *.ibd files. 64 is 64 megabytes innodb_buffer_pool_instances  0  8. On 32 bit Windows only, if innodb_buffer_pool_size is greater than 1300M, default is innodb_buffer_pool_size / 128M innodb_concurrency_tickets  500  5000 innodb_file_per_table  off  on innodb_log_file_size  5M  48M  InnoDB will always change size to match my.cnf value. Also see innodb_log_compressed_pages and binlog_row_image innodb_old_blocks_time 0  1000 1 second innodb_open_files  300  300; if innodb_file_per_table is ON, higher of table_open_cache or 300 innodb_purge_batch_size  20  300 innodb_purge_threads  0  1 innodb_stats_on_metadata  on  off join_buffer_size 128k  256k max_allowed_packet  1M  4M max_connect_errors  10  100 open_files_limit  0  5000  See note 1 query_cache_size  0  1M query_cache_type  on/1  off/0 sort_buffer_size  2M  256k sql_mode  none  NO_ENGINE_SUBSTITUTION  See later post about default my.cnf for STRICT_TRANS_TABLES sync_master_info  0  10000  Recommend: master_info_repository=table sync_relay_log  0  10000 sync_relay_log_info  0  10000  Recommend: relay_log_info_repository=table. Also see Replication Relay and Status Logs table_definition_cache  400  400 + table_open_cache / 2, capped at 2000 table_open_cache  400  2000   Also see table_open_cache_instances thread_cache_size  0  8 + max_connections/100, capped at 100 Note 1: In 5.5 there was already a rule to make open_files_limit 10 + max_connections + table_cache_size * 2 if that was higher than the user-specified value. Now uses the higher of that and (5000 or what you specify). We are also adding a new default my.cnf file and guided instructions on the key settings to adjust. More on this in a later post. We're also providing a page with suggestions for settings to improve backwards compatibility. The old example files like my-huge.cnf are obsolete. Some of the improvements are present from 5.6.6 and the rest are coming. These are ideas, and until they are in an official GA release, they are subject to change. As part of this work I reviewed every old server setting plus many hundreds of emails of feedback and testing results from inside and outside Oracle's MySQL Support team and the many excellent blog entries and comments from others over the years, including from many MySQL Gurus out there, like Baron, Sheeri, Ronald, Schlomi, Giuseppe and Mark Callaghan. With these changes we're trying to make it easier to set up the server by adjusting only a few settings that will cause others to be set. This happens only at server startup and only applies to variables where you haven't set a value. You'll see a similar approach used for the Performance Schema. The Gurus don't need this but for many newcomers the defaults will be very useful. Possibly the most unusual change is the way we vary the setting for innodb_buffer_pool_instances for 32-bit Windows. This is because we've found that DLLs with specified load addresses often fragment the limited four gigabyte 32-bit address space and make it impossible to allocate more than about 1300 megabytes of contiguous address space for the InnoDB buffer pool. The smaller requests for many pools are more likely to succeed. If you change the value of innodb_log_file_size in my.cnf you will see a message like this in the error log file at the next restart, instead of the old error message: [Warning] InnoDB: Resizing redo log from 2*64 to 5*128 pages, LSN=5735153 One of the biggest challenges for the defaults is the millions of installations on a huge range of systems, from point of sale terminals and routers though shared hosting or end user systems and on to major servers with lots of CPU cores, hundreds of gigabytes of RAM and terabytes of fast disk space. Our past defaults were for the smaller systems and these change that to larger shared hosting or shared end user systems, still with a bias towards the smaller end. There is a bias in favour of OLTP workloads, so reporting systems may need more changes. Where there is a conflict between the best settings for benchmarks and normal use, we've favoured production, not benchmarks. We're very interested in your feedback, comments and suggestions.

    Read the article

  • How to handle multi-processing of libraries which already spawn sub-processes?

    - by exhuma
    I am having some trouble coming up with a good solution to limit sub-processes in a script which uses a multi-processed library and the script itself is also multi-processed. Both, the library and script are modifiable by us. I believe the question is more about design than actual code, but for what it's worth, it's written in Python. The goal of the library is to hide implementation details of various internet routers. For that reason, the library has a "Proxy" factory method which takes the IP of a router as parameter. The factory then probes the device using a set of possible proxies. Usually, there is one proxy which immediately knows that is is able to send commands to this device. All others usually take some time to return (given a timeout). One thought was already to simply query the device for an identifier, and then select the proper proxy using that, but in order to do so, you would already need to know how to query the device. Abstracting this knowledge is one of the main purposes of the library, so that becomes a little bit of a "circular-requirement"/deadlock: To connect to a device, you need to know what proxy to use, and to know what proxy to create, you need to connect to a device. So probing the device is - as we can see - the best solution so far, apart from keeping a lookup-table somewhere. The library currently kills all remaining processes once a valid proxy has been found. And yes, there is always only one good proxy per device. Currently there are about 12 proxies. So if one create a proxy instance using the factory, 12 sub-processes are spawned. So far, this has been really useful and worked very well. But recently someone else wanted to use this library to "broadcast" a command to all devices. So he took the library, and wrote his own multi-processed script. This obviously spawned 12 * n processes where n is the number of IPs to which he broadcasted. This has given us two problems: The host on which the command was executed slowed down to a near halt. Aborting the script with CTRL+C ground the system to a total halt. Not even the hardware console responded anymore! This may be due to some Python strangeness which still needs to be investigated. Maybe related to http://bugs.python.org/issue8296 The big underlying question, is how to design a library which does multi-processing, so other applications which use this library and want to be multi-processed themselves do not run into system limitations. My first thought was to require a pool to be passed to the library, and execute all tasks in that pool. In that way, the person using the library has control over the usage of system resources. But my gut tells me that there must be a better solution. Disclaimer: My experience with multiprocessing is fairly limited. I have implemented a few straightforward which did not require access control to resources. So I have not yet any practical experience with semaphores or mutexes. p.s.: In the future, we may have enough information to do this without the probing. But the database which would contain the proper information is not yet operational. Also, the design about multiprocessing a multiprocessed library intrigues me :)

    Read the article

  • Linux Mint 10 LXDE computer to act as LTSP Server without luck

    - by Rautamiekka
    So I've tried to make our screen-broken HP laptop to also serve as LTSP Server in addition to various other tasks, without luck, which may be cuz I'm running LM10 LXDE while the instructions are for Ubuntu. Excuse my ignorance. The entire output from Terminal after installing LTSP stuff along with a Server kernel and a load of other packages: administrator@rauta-mint-turion ~ $ sudo lt ltrace ltsp-build-client ltsp-chroot ltspfs ltspfsmounter ltsp-info ltsp-localapps ltsp-update-image ltsp-update-kernels ltsp-update-sshkeys administrator@rauta-mint-turion ~ $ sudo ltsp-update-sshkeys administrator@rauta-mint-turion ~ $ sudo ltsp-update-kernels find: `/opt/ltsp/': No such file or directory administrator@rauta-mint-turion ~ $ sudo ltsp-build-client /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging: line 3: /opt/ltsp/i386/etc/ltsp_chroot: No such file or directory error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ sudo ltsp-update-image Cannot determine assigned port. Assigning to port 2000. mkdir: cannot create directory `/opt/ltsp/i386/etc/ltsp': No such file or directory /usr/sbin/ltsp-update-image: 274: cannot create /opt/ltsp/i386/etc/ltsp/update-kernels.conf: Directory nonexistent /usr/sbin/ltsp-update-image: 274: cannot create /opt/ltsp/i386/etc/ltsp/update-kernels.conf: Directory nonexistent Regenerating kernel... chroot: failed to run command `/usr/share/ltsp/update-kernels': No such file or directory Done. Configuring inetd... Done. Updating pxelinux default configuration...Done. Skipping invalid chroot: /opt/ltsp/i386 chroot: failed to run command `test': No such file or directory administrator@rauta-mint-turion ~ $ sudo ltsp-chroot chroot: failed to run command `/bin/bash': No such file or directory administrator@rauta-mint-turion ~ $ bash administrator@rauta-mint-turion ~ $ exit exit administrator@rauta-mint-turion ~ $ sudo ls /opt/ltsp i386 administrator@rauta-mint-turion ~ $ sudo ls /opt/ltsp/i386/ administrator@rauta-mint-turion ~ $ sudo ltsp-build-client NOTE: Root directory /opt/ltsp/i386 already exists, this will lead to problems, please remove it before trying again. Exiting. error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ sudo rm -rv /opt/ltsp/i386 removed directory: `/opt/ltsp/i386' administrator@rauta-mint-turion ~ $ sudo ltsp-build-client /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging: line 3: /opt/ltsp/i386/etc/ltsp_chroot: No such file or directory error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ aptitude search ltsp p fts-ltsp-ldap - LDAP LTSP module for the TFTP/Fuse supplicant p ltsp-client - LTSP client environment p ltsp-client-core - LTSP client environment (core) p ltsp-cluster-accountmanager - Account creation and management daemon for LTSP p ltsp-cluster-control - Web based thin-client configuration management p ltsp-cluster-lbagent - LTSP loadbalancer agent offers variables about the state of the ltsp server p ltsp-cluster-lbserver - LTSP loadbalancer server returns the optimal ltsp server to terminal p ltsp-cluster-nxloadbalancer - Minimal NX loadbalancer for ltsp-cluster p ltsp-cluster-pxeconfig - LTSP-Cluster symlink generator p ltsp-controlaula - Classroom management tool with ltsp clients p ltsp-docs - LTSP Documentation p ltsp-livecd - starts an LTSP live server on an Ubuntu livecd session p ltsp-manager - Ubuntu LTSP server management GUI i A ltsp-server - Basic LTSP server environment i ltsp-server-standalone - Complete LTSP server environment i A ltspfs - Fuse based remote filesystem for LTSP thin clients p ltspfsd - Fuse based remote filesystem hooks for LTSP thin clients p ltspfsd-core - Fuse based remote filesystem daemon for LTSP thin clients p python-ltsp - provides ltsp related functions administrator@rauta-mint-turion ~ $ sudo aptitude purge ltsp-server ltsp-server-standalone ltspfs The following packages will be REMOVED: debconf-utils{u} debootstrap{u} dhcp3-server{u} gstreamer0.10-pulseaudio{u} ldm-server{u} libpulse-browse0{u} ltsp-server{p} ltsp-server-standalone{p} ltspfs{p} nbd-server{u} openbsd-inetd{u} pulseaudio{u} pulseaudio-esound-compat{u} pulseaudio-module-x11{u} pulseaudio-utils{u} squashfs-tools{u} tftpd-hpa{u} 0 packages upgraded, 0 newly installed, 17 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 6,996kB will be freed. Do you want to continue? [Y/n/?] (Reading database ... 158454 files and directories currently installed.) Removing ltsp-server-standalone ... Purging configuration files for ltsp-server-standalone ... Removing ltsp-server ... Purging configuration files for ltsp-server ... dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot/ltsp' not empty so not removed. dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot' not empty so not removed. Processing triggers for man-db ... (Reading database ... 158195 files and directories currently installed.) Removing debconf-utils ... Removing debootstrap ... Removing dhcp3-server ... * Stopping DHCP server dhcpd3 [ OK ] Removing gstreamer0.10-pulseaudio ... Removing ldm-server ... Removing pulseaudio-module-x11 ... Removing pulseaudio-esound-compat ... Removing pulseaudio ... * PulseAudio configured for per-user sessions Removing pulseaudio-utils ... Removing libpulse-browse0 ... Processing triggers for man-db ... Processing triggers for ureadahead ... ureadahead will be reprofiled on next reboot Processing triggers for libc-bin ... ldconfig deferred processing now taking place (Reading database ... 157944 files and directories currently installed.) Removing ltspfs ... Processing triggers for man-db ... (Reading database ... 157932 files and directories currently installed.) Removing nbd-server ... Stopping Network Block Device server: nbd-server. Removing openbsd-inetd ... * Stopping internet superserver inetd [ OK ] Removing squashfs-tools ... Removing tftpd-hpa ... tftpd-hpa stop/waiting Processing triggers for ureadahead ... Processing triggers for man-db ... administrator@rauta-mint-turion ~ $ sudo aptitude purge ~c The following packages will be REMOVED: dhcp3-server{p} libpulse-browse0{p} nbd-server{p} openbsd-inetd{p} pulseaudio{p} tftpd-hpa{p} 0 packages upgraded, 0 newly installed, 6 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 0B will be used. Do you want to continue? [Y/n/?] (Reading database ... 157881 files and directories currently installed.) Removing dhcp3-server ... Purging configuration files for dhcp3-server ... Removing libpulse-browse0 ... Purging configuration files for libpulse-browse0 ... Removing nbd-server ... Purging configuration files for nbd-server ... Removing openbsd-inetd ... Purging configuration files for openbsd-inetd ... Removing pulseaudio ... Purging configuration files for pulseaudio ... Removing tftpd-hpa ... Purging configuration files for tftpd-hpa ... Processing triggers for ureadahead ... administrator@rauta-mint-turion ~ $ sudo aptitude install ltsp-server-standalone The following NEW packages will be installed: debconf-utils{a} debootstrap{a} ldm-server{a} ltsp-server{a} ltsp-server-standalone ltspfs{a} nbd-server{a} openbsd-inetd{a} squashfs-tools{a} The following packages are RECOMMENDED but will NOT be installed: dhcp3-server pulseaudio-esound-compat tftpd-hpa 0 packages upgraded, 9 newly installed, 0 to remove and 0 not upgraded. Need to get 0B/498kB of archives. After unpacking 2,437kB will be used. Do you want to continue? [Y/n/?] Preconfiguring packages ... Selecting previously deselected package openbsd-inetd. (Reading database ... 157868 files and directories currently installed.) Unpacking openbsd-inetd (from .../openbsd-inetd_0.20080125-4ubuntu2_i386.deb) ... Processing triggers for man-db ... Processing triggers for ureadahead ... Setting up openbsd-inetd (0.20080125-4ubuntu2) ... * Stopping internet superserver inetd [ OK ] * Starting internet superserver inetd [ OK ] Selecting previously deselected package ldm-server. (Reading database ... 157877 files and directories currently installed.) Unpacking ldm-server (from .../ldm-server_2%3a2.1.3-0ubuntu1_all.deb) ... Selecting previously deselected package debconf-utils. Unpacking debconf-utils (from .../debconf-utils_1.5.32ubuntu3_all.deb) ... Selecting previously deselected package debootstrap. Unpacking debootstrap (from .../debootstrap_1.0.23ubuntu1_all.deb) ... Selecting previously deselected package nbd-server. Unpacking nbd-server (from .../nbd-server_1%3a2.9.14-2ubuntu1_i386.deb) ... Selecting previously deselected package squashfs-tools. Unpacking squashfs-tools (from .../squashfs-tools_1%3a4.0-8_i386.deb) ... Selecting previously deselected package ltsp-server. GNU nano 2.2.4 File: /etc/ltsp/ltsp-update-image.conf # Configuration file for ltsp-update-image # By default, do not compress the image # as it's reported to make it unstable NO_COMP="-noF -noD -noI -no-exports" [ Switched to /etc/ltsp/ltsp-update-image.conf ] administrator@rauta-mint-turion ~ $ ls /opt/ firefox/ ltsp/ mint-flashplugin/ administrator@rauta-mint-turion ~ $ ls /opt/ltsp/i386/ administrator@rauta-mint-turion ~ $ ls /opt/ltsp/ i386 administrator@rauta-mint-turion ~ $ sudo ltsp ltsp-build-client ltsp-chroot ltspfs ltspfsmounter ltsp-info ltsp-localapps ltsp-update-image ltsp-update-kernels ltsp-update-sshkeys administrator@rauta-mint-turion ~ $ sudo ltsp-build-client NOTE: Root directory /opt/ltsp/i386 already exists, this will lead to problems, please remove it before trying again. Exiting. error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ ^C administrator@rauta-mint-turion ~ $ sudo aptitude purge ltsp ltspfs ltsp-server ltsp-server-standalone administrator@rauta-mint-turion ~ $ sudo aptitude purge ltsp-server The following packages will be REMOVED: ltsp-server{p} 0 packages upgraded, 0 newly installed, 1 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 1,073kB will be freed. The following packages have unmet dependencies: ltsp-server-standalone: Depends: ltsp-server but it is not going to be installed. The following actions will resolve these dependencies: Remove the following packages: 1) ltsp-server-standalone Accept this solution? [Y/n/q/?] The following packages will be REMOVED: debconf-utils{u} debootstrap{u} ldm-server{u} ltsp-server{p} ltsp-server-standalone{a} ltspfs{u} nbd-server{u} openbsd-inetd{u} squashfs-tools{u} 0 packages upgraded, 0 newly installed, 9 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 2,437kB will be freed. Do you want to continue? [Y/n/?] (Reading database ... 158244 files and directories currently installed.) Removing ltsp-server-standalone ... (Reading database ... 158240 files and directories currently installed.) Removing ltsp-server ... Purging configuration files for ltsp-server ... dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot/ltsp' not empty so not removed. dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot' not empty so not removed. Processing triggers for man-db ... (Reading database ... 157987 files and directories currently installed.) Removing debconf-utils ... Removing debootstrap ... Removing ldm-server ... Removing ltspfs ... Removing nbd-server ... Stopping Network Block Device server: nbd-server. Removing openbsd-inetd ... * Stopping internet superserver inetd [ OK ] Removing squashfs-tools ... Processing triggers for man-db ... Processing triggers for ureadahead ... administrator@rauta-mint-turion ~ $ sudo aptitude purge ~c The following packages will be REMOVED: ltsp-server-standalone{p} nbd-server{p} openbsd-inetd{p} 0 packages upgraded, 0 newly installed, 3 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 0B will be used. Do you want to continue? [Y/n/?] (Reading database ... 157871 files and directories currently installed.) Removing ltsp-server-standalone ... Purging configuration files for ltsp-server-standalone ... Removing nbd-server ... Purging configuration files for nbd-server ... Removing openbsd-inetd ... Purging configuration files for openbsd-inetd ... Processing triggers for ureadahead ... administrator@rauta-mint-turion ~ $ sudo rm -rv /var/lib/t teamspeak-server/ tftpboot/ transmission-daemon/ administrator@rauta-mint-turion ~ $ sudo rm -rv /var/lib/tftpboot removed `/var/lib/tftpboot/ltsp/i386/pxelinux.cfg/default' removed directory: `/var/lib/tftpboot/ltsp/i386/pxelinux.cfg' removed directory: `/var/lib/tftpboot/ltsp/i386' removed directory: `/var/lib/tftpboot/ltsp' removed directory: `/var/lib/tftpboot' administrator@rauta-mint-turion ~ $ sudo find / -name "ltsp" /opt/ltsp administrator@rauta-mint-turion ~ $ sudo rm -rv /opt/ltsp removed directory: `/opt/ltsp/i386' removed directory: `/opt/ltsp' administrator@rauta-mint-turion ~ $ sudo aptitude install ltsp-server-standalone The following NEW packages will be installed: debconf-utils{a} debootstrap{a} ldm-server{a} ltsp-server{a} ltsp-server-standalone ltspfs{a} nbd-server{a} openbsd-inetd{a} squashfs-tools{a} The following packages are RECOMMENDED but will NOT be installed: dhcp3-server pulseaudio-esound-compat tftpd-hpa 0 packages upgraded, 9 newly installed, 0 to remove and 0 not upgraded. Need to get 0B/498kB of archives. After unpacking 2,437kB will be used. Do you want to continue? [Y/n/?] Preconfiguring packages ... Selecting previously deselected package openbsd-inetd. (Reading database ... 157868 files and directories currently installed.) Unpacking openbsd-inetd (from .../openbsd-inetd_0.20080125-4ubuntu2_i386.deb) ... Processing triggers for man-db ... GNU nano 2.2.4 New Buffer GNU nano 2.2.4 File: /etc/ltsp/dhcpd.conf # # Default LTSP dhcpd.conf config file. # authoritative; subnet 192.168.2.0 netmask 255.255.255.0 { range 192.168.2.70 192.168.2.79; option domain-name "jarvinen"; option domain-name-servers 192.168.2.254; option broadcast-address 192.168.2.255; option routers 192.168.2.254; # next-server 192.168.0.1; # get-lease-hostnames true; option subnet-mask 255.255.255.0; option root-path "/opt/ltsp/i386"; if substring( option vendor-class-identifier, 0, 9 ) = "PXEClient" { filename "/ltsp/i386/pxelinux.0"; } else { filename "/ltsp/i386/nbi.img"; } } [ Wrote 22 lines ] administrator@rauta-mint-turion ~ $ sudo service dhcp3-server start * Starting DHCP server dhcpd3 [ OK ] administrator@rauta-mint-turion ~ $ sudo ltsp-build-client /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging: line 3: /opt/ltsp/i386/etc/ltsp_chroot: No such file or directory error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ sudo cat /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging case "$MODE" in after-install) echo LTSP_CHROOT=$ROOT >> $ROOT/etc/ltsp_chroot ;; esac administrator@rauta-mint-turion ~ $ cd $ROOT/etc/ltsp_chroot bash: cd: /etc/ltsp_chroot: No such file or directory administrator@rauta-mint-turion ~ $ cd $ROOT/etc/ administrator@rauta-mint-turion /etc $ ls acpi chatscripts emacs group insserv.conf.d logrotate.conf mysql php5 rc6.d smbnetfs.conf UPower adduser.conf ConsoleKit environment group- iproute2 logrotate.d nanorc phpmyadmin rc.local snmp usb_modeswitch.conf alternatives console-setup esound grub.d issue lsb-base nbd-server pm rcS.d sound usb_modeswitch.d anacrontab cron.d firefox gshadow issue.net lsb-base-logging.sh ndiswrapper pnm2ppa.conf request-key.conf ssh ushare.conf apache2 cron.daily firefox-3.5 gshadow- java lsb-release netscsid.conf polkit-1 resolvconf ssl vga apm cron.hourly firestarter gtk-2.0 java-6-sun ltrace.conf network popularity-contest.conf resolv.conf sudoers vim apparmor cron.monthly fonts gtkmathview kbd ltsp NetworkManager ppp rmt sudoers.d vlc apparmor.d crontab foomatic gufw kernel lxdm networks printcap rpc su-to-rootrc vsftpd.conf apport cron.weekly fstab hal kernel-img.conf magic nsswitch.conf profile rsyslog.conf sweeprc w3m apt crypttab ftpusers hdparm.conf kerneloops.conf magic.mime ntp.conf profile.d rsyslog.d sysctl.conf wgetrc at.deny cups fuse.conf host.conf kompozer mailcap obex-data-server protocols samba sysctl.d wildmidi auto-apt dbconfig-common gai.conf hostname ldap mailcap.order ODBCDataSources psiconv sane.d teamspeak-server wodim.conf avahi dbus-1 gamin hosts ld.so.cache manpath.config odbc.ini pulse screenrc terminfo wpa_supplicant bash.bashrc debconf.conf gconf hosts.allow ld.so.conf menu openal purple securetty thunderbird X11 bash_completion debian_version gdb hosts.deny ld.so.conf.d menu-methods openoffice python security timezone xdg bash_completion.d default gdm hp legal mime.types opt python2.6 sensors3.conf transmission-daemon xml bindresvport.blacklist defoma ghostscript ifplugd lftp.conf mke2fs.conf pam.conf python2.7 sensors.d ts.conf xulrunner-1.9.2 blkid.conf deluser.conf gimp inetd.conf libpaper.d modprobe.d pam.d python3.1 services ucf.conf zsh_command_not_found blkid.tab depmod.d gnome init libreoffice modules pango rc0.d sgml udev bluetooth dhcp gnome-system-tools init.d linuxmint motd papersize rc1.d shadow ufw bonobo-activation dhcp3 gnome-vfs-2.0 initramfs-tools locale.alias mplayer passwd rc2.d shadow- updatedb.conf ca-certificates dictionaries-common gnome-vfs-mime-magic inputrc localtime mtab passwd- rc3.d shells update-manager ca-certificates.conf doc-base gre.d insserv logcheck mtab.fuselock pcmcia rc4.d skel update-motd.d calendar dpkg groff insserv.conf login.defs mtools.conf perl rc5.d smb2www update-notifier administrator@rauta-mint-turion /etc $ cd ltsp/ administrator@rauta-mint-turion /etc/ltsp $ ls dhcpd.conf ltsp-update-image.conf administrator@rauta-mint-turion /etc/ltsp $ cat dhcpd.conf # # Default LTSP dhcpd.conf config file. # authoritative; subnet 192.168.2.0 netmask 255.255.255.0 { range 192.168.2.70 192.168.2.79; option domain-name "jarvinen"; option domain-name-servers 192.168.2.254; option broadcast-address 192.168.2.255; option routers 192.168.2.254; # next-server 192.168.0.1; # get-lease-hostnames true; option subnet-mask 255.255.255.0; option root-path "/opt/ltsp/i386"; if substring( option vendor-class-identifier, 0, 9 ) = "PXEClient" { filename "/ltsp/i386/pxelinux.0"; } else { filename "/ltsp/i386/nbi.img"; } } administrator@rauta-mint-turion /etc/ltsp $

    Read the article

  • pxe boot fails with message: no DEFAULT or UI configuration directive found

    - by spockaroo
    I am trying to pxe-boot a machine (client), and in the process I am trying to setup a tftp server that this machine can boot off. On the server, which runs Ubuntu 10.10, I have setup dhcp, dns, nfs, and tftp-hpa servers. All the servers/deamons start fine. I tested the tftp server by using a tftp client and downloading a file that the server directory hosts. My /etc/xinet.d/tftp looks like this service tftp { disable = no socket_type = dgram wait = yes user = nobody server = /usr/sbin/in.tftpd server_args = -v -s /var/lib/tftpboot only_from = 10.1.0.0/24 interface = 10.1.0.1 } My /etc/default/tftpd-hpa looks like this RUN_DAEMON="yes" OPTIONS="-l -s /var/lib/tftpboot" TFTP_USERNAME="tftp" TFTP_DIRECTORY="/var/lib/tftpboot" TFTP_ADDRESS="0.0.0.0:69" TFTP_OPTIONS="--secure" My /var/lib/tftpboot/ directory looks like this initrd.img-2.6.35-25-generic-pae vmlinuz-2.6.35-25-generic-pae pxelinux.0 pxelinux.cfg -- default I did sudo chmod 644 /var/lib/tftpboot/pxelinux.cfg/default chmod 755 /var/lib/tftpboot/initrd.img-2.6.35-25-generic-pae chmod 755 /var/lib/tftpboot/vmlinuz-2.6.35-25-generic-pae /var/lib/tftpboot/pxelinux.cfg has the following contents SERIAL 0 19200 0 LABEL linux KERNEL vmlinuz-2.6.35-25-generic-pae APPEND root=/dev/nfs initrd=initrd.img-2.6.35-25-generic-pae nfsroot=10.1.0.1:/nfsroot ip=dhcp console=ttyS0,19200n8 rw I copied /var/lib/tftpboot/pxelinux.0 from /usr/lib/syslinux/ after installing the package syslinux-common. Also just for completeness, /etc/dhcp3/dhcpd.conf the following lines (relevant to this interface) subnet 10.1.0.0 netmask 255.255.255.0 { range 10.1.0.100 10.1.0.240; option routers 10.1.0.1; option broadcast-address 10.1.0.255; option domain-name-servers 10.1.0.1; filename "pxelinux.0"; } When I boot the client machine, and watch the output over the serial port, I notice that the client requests an ip address from the server and gets it. Then I see TFTP being displayed - indicating that it is trying to connect to the TFTP server. This succeeds, and I see TFTP.|, which return immediately displaying the following message PXELINUX 4.01 debian-20100714 Copyright (C) 1994-2010 H. Peter Anvin et al No DEFAULT or UI configuration directive found! boot: /var/log/syslog shows Feb 20 15:24:05 ch in.tftpd[2821]: tftp: client does not accept options What option is it talking about in the syslog? I assume it is referring to OPTIONS or TFTP_OPTIONS, but what am I doing wrong?

    Read the article

  • DHCP "no answer" on CentOS 6.4

    - by Kev
    I installed a DHCP server (yum install dhcp) and this is my conf: # create new # specify domain name option domain-name "mydomain.name"; # specify DNS's hostname or IP address option domain-name-servers 10.0.1.1, 10.0.1.2; option ntp-servers 10.0.1.1, 10.0.1.2; allow unknown-clients; # default lease time default-lease-time 2628000; # max lease time max-lease-time 2628000; # about a month # this DHCP server to be declared valid authoritative; # specify network address and subnet mask subnet 10.0.0.0 netmask 255.0.0.0 { # specify the range of lease IP address range dynamic-bootp 10.0.2.1 10.0.2.50; # specify broadcast address option broadcast-address 10.255.255.255; # specify default gateway option routers 10.0.0.1; allow unknown-clients; } service dhcp start reports [ OK ]. Yet, if I disable my other DHCP server (Win2k3) and get a client to try renewing its IP lease, it times out. So I installed dhcping. No matter what options I try, including directing dhcping at my server, adding a client address in the range, adding my hardware address, it replies 'no answer'. I'm also trying -i since that seems to be more akin to what a WinXP client would try to do, based on /var/log/messages. It logs the attempts (from dhcping here) as: Oct 24 18:55:13 newdc dhcpd: DHCPINFORM from 10.0.2.15 via eth0:4 Oct 24 18:55:13 newdc dhcpd: DHCPACK to 10.0.2.15 (00:11:25:66:4e:7f) via eth0:4 Oct 24 18:55:13 newdc dhcpd: DHCPINFORM from 10.0.2.15 via eth0:3 Oct 24 18:55:13 newdc dhcpd: DHCPACK to 10.0.2.15 (00:11:25:66:4e:7f) via eth0:3 Oct 24 18:55:13 newdc dhcpd: DHCPINFORM from 10.0.2.15 via eth0 Oct 24 18:55:13 newdc dhcpd: DHCPACK to 10.0.2.15 (00:11:25:66:4e:7f) via eth0 The :3 and :4 are because I have a few extra Host(A) records for this server so it responds on more than one IP for our intranet app. No answer? It sounds like it should be getting three answers...no? (And if that's the problem, how do I limit the DHCP service to replying from eth0?)

    Read the article

  • Home and Small to Medium Enterprise network manufacturer choice, Netgear, Linksys or D-Link ?

    - by Kedare
    (Please don't close this post, it's a serious post so... Be cool, no trolls please, I need an answer ;p) Hello, I am looking for an alternative to Cisco (too expensive for me !) for semi-pro utilization (at home but with advanced feature (I'm studying in IT)) and in small/medium enterprises. I think I will choose between LinkSys (Including Cisco Small Business), Netgear and D-Link, but I've never really used these products, that what I need is a manufacturer that make "almost" all type of networking equipment (Like Cisco but cheaper..), here are my needs : I need almost all my products to be rackable I need a good warranty (Netgear lifetime waranty rulez!) I need an "unified" network environment I made a little comparison of the characteristics that interest me after hours of search on Internet (based on result found on many websites): (Prices are based on the ldlc-pro.com french website) Hotline/Support Quality: Netgear : Not so bad Linksys : Not so bad D-Link : Poor! Most common Warranty: Netgear : Unlimited Lifetime Warranty! Linksys : Limited 3 years warranty D-Link : Limited 5 years warranty (Unlimited in US but I'm on France :(...) VPN protocols compatibles with routers on endpoint mode: Netgear : Only IPSEC :( Linksys : IPSEC, PPTP, L2TP D-Link : IPSEC, PPTP, L2TP Cheaper 8 ports Gb switch : Netgear : 30€ Linksys : 47€ D-Link : 30€ Cheaper 48 ports + 1Gb uplink(s) administrable switch : Netgear : 263€ Linksys : 630€ D-Link : 600€ Cheaper VPN router : Netgear : 100€ Linksys : 80€ D-Link : 60€ Cheaper rackable switch : Netgear : 50€ Linksys : 87€ D-Link : 50€ Cheaper rackable and administrable switch : Netgear : 120€ Linksys : 370€ D-Link : 171€ Netgear and D-Link are in the same range of price, where Linksys is more expensives. I've searched for some other criteria ( the full comparison is here, in french with shop/source links: http://forums.jeuxonline.info/showthread.php?t=1072280 ) and made a final score for each manufacturer : SCORE including IP camera sub-score: Netgear : 6.2/10 Linksys : 7.3/10 D-Link : 7.0/10 SCORE excluding IP camera sub-score: Netgear : 6.9/10 Linksys : 7.0/10 D-Link : 6.7/10 On both case, Linksys wins. So here is my little comparison, but because I've never really used these stuffs, I need your help to make a decision on witch manufacturer choose for both my personnal and corporate use. So here are the questions : What manufacturer do you recommend me (Not cisco (except Small business)) ? Why ? Have you called the call center of the customer support of one of these manufacturer ? How it was ? Did you had problems or bad experiences with these equipments ? Any other advices ? ;) Thank you !

    Read the article

  • gmail dkim=neutral (no signature)

    - by Bretticus
    After testing much and retracing my steps, I still cannot get google mail to validate. My mail server is Debian 5.0 with exim Exim version 4.72 #1 built 31-Jul-2010 08:12:17 Copyright (c) University of Cambridge, 1995 - 2007 Berkeley DB: Berkeley DB 4.8.24: (August 14, 2009) Support for: crypteq iconv() IPv6 PAM Perl Expand_dlfunc GnuTLS move_frozen_messages Content_Scanning DKIM Old_Demime Lookups: lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmnz dnsdb dsearch ldap ldapdn ldapm mysql nis nis0 passwd pgsql sqlite Authenticators: cram_md5 cyrus_sasl dovecot plaintext spa Routers: accept dnslookup ipliteral iplookup manualroute queryprogram redirect Transports: appendfile/maildir/mailstore/mbx autoreply lmtp pipe smtp Fixed never_users: 0 Size of off_t: 8 GnuTLS compile-time version: 2.4.2 GnuTLS runtime version: 2.4.2 Configuration file is /var/lib/exim4/config.autogenerated My remote smtp transport configuration: remote_smtp: debug_print = "T: remote_smtp for $local_part@$domain" driver = smtp helo_data = mailer.mydomain.com dkim_domain = mydomain.com dkim_selector = mailer dkim_private_key = /etc/exim4/dkim/mailer.mydomain.com.key dkim_canon = relaxed .ifdef REMOTE_SMTP_HOSTS_AVOID_TLS hosts_avoid_tls = REMOTE_SMTP_HOSTS_AVOID_TLS .endif .ifdef REMOTE_SMTP_HEADERS_REWRITE headers_rewrite = REMOTE_SMTP_HEADERS_REWRITE .endif .ifdef REMOTE_SMTP_RETURN_PATH return_path = REMOTE_SMTP_RETURN_PATH .endif .ifdef REMOTE_SMTP_HELO_FROM_DNS helo_data=REMOTE_SMTP_HELO_DATA .endif The path to my private key is correct. I see a DKIM header in my messages as they end up in my gmail account: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mydomain.com; s=mailer; h=Content-Type:MIME-Version:Message-ID:Date:Subject:Reply-To:To:From; bh=nKgQAFyGv<snip>tg=; b=m84lyYvX6<snip>RBBqmW52m1ce2g=; However, gmail headers always report dkim=neutral (no signature): dkim=neutral (no signature) [email protected] My DNS results: dig +short txt mailer._domainkey.mydomain.com mailer._domainkey. mydomain.com descriptive text "v=DKIM1\; k=rsa\; t=y\; p=LS0tLS1CRUdJ<snip>M0RRRUJBUVV" "BQTRHTkFEQ0J<snip>GdLamdaaG" "JwaFZkai93b3<snip>laSCtCYmdsYlBrWkdqeVExN3gxN" "mpQTzF6OWJDN3hoY21LNFhaR0NjeENMR0FmOWI4Z<snip>tLQo=" Note that the base64 public key is 364 chars long so I had to break up the key using bind9. $ORIGIN _domainkey. mydomain.com. mailer TXT ("v=DKIM1; k=rsa; t=y; p=LS0tLS1CRUdJTiBQVUJM<snip>U0liM0RRRUJBUVV" "BQTRHTkFEQ0JpUUtCZ1<snip>15MGdLamdaaG" "JwaFZkai93b3lDK21MR<snip>YlBrWkdqeVExN3gxN" "mpQTzF6OWJDN3hoY21L<snip>Ci0tLS0tRU5E" "IFBVQkxJQyBLRVktLS0tLQo=") Can anyone point me in the right direction? I would really appreciate it.

    Read the article

  • dnsmasq acts as the DHCP server for selected nodes overriding the existing DHCP server on the same LAN?

    - by user183394
    I am trying to set up a small "lab" at home. Like many modern homes, I have a regular DSL service which comes with a 2Wire 3600HGV router, which acts also as a DHCP server. Since I would like to PXE boot a few computers in my "lab" The 2Wire is inflexible to adjustments that I want to do I have used dnsmasq at work so I would like to use dnsmasq as the DHCP server for the few nodes in my "lab" if feasible. In the dnsmasq man page, there is the following: [...] -K, --dhcp-authoritative (IPv4 only) Should be set when dnsmasq is definitely the only DHCP server on a network. It changes the behaviour from strict RFC compliance so that DHCP requests on unknown leases from unknown hosts are not ignored. This allows new hosts to get a lease without a tedious timeout under all circumstances. It also allows dnsmasq to rebuild its lease database without each client needing to reacquire a lease, if the database is lost. [...] As far as I know, the ISC DHCP server can use the following to do what I would like to accomplish: authoritative; [...] subnet 192.168.1.0 netmask 255.255.255.0 { host nb0 { # only give DHCP information to this computer: hardware ethernet e8:9a:8f:17:70:42; fixed-address 192.168.1.10; option subnet-mask 255.255.255.0; option routers 192.168.1.254; option domain-name-servers 192.168.1.254; # Non-essential DHCP options filename "/pxelinux.0"; } [...] But I much prefer dnsmasq's "all-in-one-ness". My question: do I have to couple the -K option with something else? As shown in the example above, the ISC DHCP server requires the mac addresses of managed nodes to be explicitly specified. Does dnsmasq have something similar? FYI, the machine on which I plan to run dnsmasq runs CentOS 6.3 64bit. It has a statically assigned IP address: 192.168.1.3.

    Read the article

  • Network is going down once per day

    - by Charly
    Once per day the network on eth0 is going down and we need to do sudo ifdown eth0; sudo ifup eth0 to get the network up. Here is the syslog: Feb 11 12:48:01 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 12:52:35 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 12:56:23 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:00:28 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:04:29 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:09:16 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:13:53 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:18:16 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:22:25 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:26:52 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:30:44 www-tech-1 dhclient: DHCPREQUEST of address> on eth0 to 131.121.113.228 port 67 Feb 11 13:31:49 www-tech-1 dhclient: There is already a pid file /var/run/dhclient.eth0.pid with pid 3198 Feb 11 13:31:49 www-tech-1 dhclient: Listening on LPF/eth0/00:e0:81:49:fc:e0 Feb 11 13:31:49 www-tech-1 dhclient: Sending on LPF/eth0/00:e0:81:49:fc:e0 Feb 11 13:31:49 www-tech-1 dhclient: DHCPRELEASE on eth0 to 131.121.113.228 port 67 Feb 11 13:31:49 www-tech-1 dhclient: There is already a pid file /var/run/dhclient.eth0.pid with pid 134519072 Feb 11 13:31:50 www-tech-1 dhclient: Listening on LPF/eth0/00:e0:81:49:fc:e0 Feb 11 13:31:50 www-tech-1 dhclient: Sending on LPF/eth0/00:e0:81:49:fc:e0 Feb 11 13:31:52 www-tech-1 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8 Feb 11 13:31:52 www-tech-1 dhclient: DHCPREQUEST of 131.121.14.17 on eth0 to 255.255.255.255 port 67 Feb 11 13:31:53 www-tech-1 kernel: [265383.991682] eth0: no IPv6 routers present Please check the last portion of this syslog. Can anybody help me?

    Read the article

  • How can I connect DLNA devices through NAT?

    - by Bob
    I have a Windows 7 PC running Serviio as a DLNA server. I have a Samsung I9100G running Skifta as a DLNA renderer (client). My network topology: At the moment, I can connect and watch my videos fine if the phone is on router #2. The server is on a wired network with #2. Router #1 is 192.168.1.1, router #2 is 192.168.2.1 (192.168.1.2) and router #3 is 192.168.3.1 (192.168.1.3). In other words, each router has its own subnet, using NAT - their "modem" port is connected with a "LAN" port on the modem/router 1. What I want to do is be able to connect to the DLNA server if the renderer is connected to router #1/#3 - #1 is on the WAN side of #2, while #3 is even further separated. I'll settle for just #1 working, though. Normally, I would just forward the appropriate ports, and everything would work fine. However, (apparently) DLNA uses UPnP, which I am unfamiliar with. I tried enabling UPnP on router #2, but that did not seem not change anything. It's a Belkin F5D7230-4 6000 - there's reported issues with UPnP on F5D7230-4 7000. UPnP is already enabled on router #1 - a Billion BiPAC 7700N. I've also tried the built in DLNA renderer/server/controller on my phone, Samsung AllShare. It can see the server on router #2 and browse files, but has issues playing or downloading them. It also can't see the server on the other two networks. I'm currently using Skifta/s "local" mode. "Remote" mode requires an account, which I don't really want to create if not necessary. Is it possible too do what I'm trying to do? If no, are there workarounds? If yes, how do I do it? Is my server the issue? The renderer (client)? The router(s)? My method? I can change just about anything except the routers.

    Read the article

  • How do I protect a low budget network from rogue DHCP servers?

    - by Kenned
    I am helping a friend manage a shared internet connection in an apartment buildling with 80 apartments - 8 stairways with 10 apartments in each. The network is laid out with the internet router at one end of the building, connected to a cheap non-managed 16 port switch in the first stairway where the first 10 apartments are also connected. One port is connected to another 16 port cheapo switch in the next stairway, where those 10 apartments are connected, and so forth. Sort of a daisy chain of switches, with 10 apartments as spokes on each "daisy". The building is a U-shape, approximately 50 x 50 meters, 20 meters high - so from the router to the farthest apartment it’s probably around 200 meters including up-and-down stairways. We have a fair bit of problems with people hooking up wifi-routers the wrong way, creating rogue DHCP servers which interrupt large groups of the users and we wish to solve this problem by making the network smarter (instead of doing a physical unplugging binary search). With my limited networking skills, I see two ways - DHCP-snooping or splitting the entire network into separate VLANS for each apartment. Separate VLANS gives each apartment their own private connection to the router, while DHCP snooping will still allow LAN gaming and file sharing. Will DHCP snooping work with this kind of network topology, or does that rely on the network being in a proper hub-and-spoke-configuration? I am not sure if there are different levels of DHCP snooping - say like expensive Cisco switches will do anything, but inexpensive ones like TP-Link, D-Link or Netgear will only do it in certain topologies? And will basic VLAN support be good enough for this topology? I guess even cheap managed switches can tag traffic from each port with it’s own VLAN tag, but when the next switch in the daisy chain receives the packet on it’s “downlink” port, wouldn’t it strip or replace the VLAN tag with it’s own trunk-tag (or whatever the name is for the backbone traffic). Money is tight, and I don’t think we can afford professional grade Cisco (I have been campaigning for this for years), so I’d love some advice on which solution has the best support on low-end network equipment and if there are some specific models that are recommended? For instance low-end HP switches or even budget brands like TP-Link, D-Link etc. If I have overlooked another way to solve this problem it is due to my lack of knowledge. :)

    Read the article

  • How to grow to be global sysadmin of an organization?

    - by user64729
    Bit of a non-technical question but I have seen questions of the career development type on here before so hopefully it is fine. I work for a fast growing but still small organization (~65 employees). I have been their external sysadmin for a while now, looking after hosted Linux servers and infrastructure. In the past 12 months I have been transforming into the internal sysadmin for our office too. I'm currently studying Cisco CCNA to cover the demands of being an internal sysadmin and looking after the office LAN, routers, switches and VPNs. Now they want me to look after the global sysadmin function of the organization as a whole. The organization has 3 offices in total, 2 in the UK and 1 in the US. I work in one of the UK offices. The other offices are primarily Windows desktops with AD domain shops. My office is primarily a Linux shop with a file-server and NFS/NIS (no AD domain for the Windows desktops yet but it's in the works). Each other office has a sysadmin which in theory I am supposed to supervise but in reality each is independent. I have a very competent junior sysadmin working with me who shares the day-to-day tasks and does some of the longer term projects with my supervision. My boss has asked me how to grow from being the external sysadmin to the global sysadmin. I am to ponder this and then report back to him on how to achieve this. My current thoughts are: Management training or professional development - eg. reading books such as "Influencer" and "7 Habits". Also I feel I should take steps to improving communication skills since a senior person is expected to talk and speak out more often. Learn more about Windows and Active Directory - I'm an LPI-certified guy and have a lot of experience in Linux (Ubuntu or desktop, Debian/Ubuntu as server). Since the other offices are mainly Windows-domains it makes sense to skill-up in that area so I can understand what the other admins are talking about. Talk to previous colleagues who have are are in this role already - to try and get the benefit of their experience. Produce an "IT Roadmap" or similar that maps out where we want the organization to be and when, plotted out over the next couple of years with regards to internal and external infrastructure. I have produced a "Security roadmap" already which does cover some of these things. I guess this can summed up as "thinking more strategically"? I'd appreciate comments from anyone who has been through a similar situation, thanks.

    Read the article

  • Why do Ping and Dig provide different IP address than nslookup?

    - by user1032531
    When pinging my domain name which points to my home public IP from two different servers on my LAN, it shows them pinging different IP. Further investigation shows dig and nslookup providing different results. See below. A little history. My IP used to be 11.22.33.444 and is hosted by Comcast. I changed routers, and it somehow got changed to 55.66.77.888. I've since updated my 1and1 domain name to point to the 55.66.77.888. desktop is a basic server, runs the web server, and connects wirelessly to my LAN. laptop is a GUI and connected via CAT5. Both operate Centos6.4. My old router was a D-Link, and used their "Virtual Server" feature to pass port 80 to desktop. My new router is a Linksys, and I use their "Port Forwarding" feature to pass port 80 to desktop (however, I haven't gotten this part working yet). What is going on??? Why the different IPs? Obviously, it most somehow be stored on the server, but why does the actual machine even know the public IP since it is on a LAN? How do I purge the old IP? [root@desktop etc]# dig +short myDomain.com 11.22.33.444 [root@desktop etc]# nslookup www.myDomain.com Server: 8.8.8.8 Address: 8.8.8.8#53 Non-authoritative answer: Name: www.myDomain.com Address: 55.66.77.888 [root@desktop etc]# dig myDomain.com ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> myDomain.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13822 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;myDomain.com. IN A ;; ANSWER SECTION: myDomain.com. 16031 IN A 11.22.33.444 ;; Query time: 21 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) ;; WHEN: Mon Oct 21 04:36:52 2013 ;; MSG SIZE rcvd: 44 [root@desktop etc]# [root@laptop ~]# dig +short myDomain.com 55.66.77.888 [root@laptop ~]# nslookup www.myDomain.com Server: 192.168.0.1 Address: 192.168.0.1#53 Non-authoritative answer: Name: www.myDomain.com Address: 55.66.77.888 [root@laptop ~]#

    Read the article

  • Assign fixed IP address via DHCP by DNS lookup

    - by Janoszen
    Preface I'm building a virtualization environment with Ubuntu 14.04 and LXC. I don't want to write my own template since the upgrade from 12.04 to 14.04 has shown that backwards compatibility is not guaranteed. Therefore I'm deploying my virtual machines via lxc-create, using the default Ubuntu template. The DNS for the servers is provided by Amazon Route 53, so no local DNS server is needed. I also use Puppet to configure my servers, so I want to keep the manual effort on the deployment minimal. Now, the default Ubuntu template assigns IP addresses via DHCP. Therefore, I need a local DHCP server to assign IP addresses to the nodes, so I can SSH into them and get Puppet running. Since Puppet requires a proper DNS setup, assigning temporary IP addresses is not an option, the client needs to get the right hostname and IP address from the start. Question What DHCP server do I use and how do I get it to assign the IP address based only on the host-name DHCP option by performing a DNS lookup on that very host name? What I've tried I tried to make it work using the ISC DHCP server, however, the manual clearly states: Please be aware that only the dhcp-client-identifier option and the hardware address can be used to match a host declaration, or the host-identifier option parameter for DHCPv6 servers. For example, it is not possible to match a host declaration to a host-name option. This is because the host-name option cannot be guaranteed to be unique for any given client, whereas both the hardware address and dhcp-client-identifier option are at least theoretically guaranteed to be unique to a given client. I also tried to create a class that matches the hostname like this: class "my-client-name" { match if option host-name = "my-client-name"; fixed-address my-client-name.my-domain.com; } Unfortunately the fixed-address option is not allowed in class statements. I can replace it with a 1-size pool, which works as expected: subnet 10.103.0.0 netmask 255.255.0.0 { option routers 10.103.1.1; class "my-client-name" { match if option host-name = "my-client-name"; } pool { allow members of "my-client-name"; range 10.103.1.2 10.103.1.2; } } However, this would require me to administer the IP addresses in two places (Amazon Route53 and the DHCP server), which I would prefer not to do. About security Since this is only used in the bootstrapping phase on an internal network and is then replaced by a static network configuration by Puppet, this shouldn't be an issue from a security standpoint. I am, however, aware that the virtual machine bootstraps with "ubuntu:ubuntu" credentials, which I intend to fix once this is running.

    Read the article

  • What "pieces" are needed in order to set up a cluster of physical servers?

    - by Chris Dutrow
    Background: Currently, we use Rackspace cloud servers. We have no intention to stop using them, but would like to look into setting up a cluster of physical servers (probably desktop computers in the $400 range with 8gb memory each) to offset some of our load and work as a secondary, more powerful, less reliable system. To put things in perspective, we can buy comparable desktop computers for the same price as we pay in one month to rent them on Rackspace Cloud. I understand that this is generally a dumb idea. However, in this particular instance, the server cluster is needed for its computation power. It is not mission-critical, it does not host a consumer-facing website, and if it goes down for a day or two, its not really a problem. Currently, we have access to business class verizon fios. If I understand correctly, we can get at least 25 dedicated IP addresses with this service, this should be enough. Requirements: Each server runs Linux Centos 6.3 Some of the servers run Python and execute processes from a task queue (Redis or RabbitMQ) Some of the servers are capable of serving static files and Python driven REST APIs Some of the servers host a Cassandra database cluster One or more of the servers are a Redis database servers One or more of the servers are PostgreSQL servers Questions: What kind of router or switch is needed? We would like the computers to be able to communicate effectively with each other via internal IP addresses. This is especially important for communicating with servers hosting Redis that need to be able to respond to requests very quickly. Are there special switches or routers that need to be used to connect the servers together? Are Desktop computers ok for this? We have found that we are mostly RAM-bottle necked, I understand that some servers have highly superior CPUs, but I'm not sure we need CPU power as much as we need RAM, which is cheap in Desktop computers. Will we have problems with the WIFI cards in the desktops or any other unexpected hardware limitation? What tools should be used to "image" the servers. For example, when we get an installation right for a Redis server or Cassandra node, are there tools that come with Linux Centos 6.3 to image the server to a USB drive or something like that? Or do we need to use some other software for this? What other things are we missing that we should be concerned about? Thanks so much!

    Read the article

  • Ubuntu Server 10.04 Heavy Network Traffic causes disconnect

    - by K Vaughan
    I'm currently running a headless Ubuntu 10.04 server. Installed is the LAMP stack, Joomla, Virtualbox, phpvirtualbox, webmin and proFTP.. It resolves the IP address so I can access it remotely (either the apache2 webserver or the FTP) using DDClient. Any packages installed have been installed using apt-get. Webmin, although discouraged in Ubuntu Server, is used mostly to administer the webserver aspect. This issue also appeared when I was using Ubuntu Server 10.10. After periods of heavy network traffic, whether local or remote, the connect drops. I'm talking specifically about the transfer of files via FTP, SCP or Samba (the latter of which I seldom use). There is no response to ping or ssh. I can't FTP to the server nor can I load the website. There are times when the server has been on for a few days and everything runs fine because I haven't accessed it much, if at all (thus not much network traffic). I've gone through a few hardware changes although I don't believe this has cause the issue: this has been happening long before I made any changes. At first I thought it was my ISP-provided router blocking traffic because of some kind of misconfiguration (perhaps assuming it was some kind of DoS attack). I've changed routers and still found no success. I've checked syslog, dmesg and kern.log for warnings but have uncovered none. I've ran memtest via the GRUB2 menu at boot and once it turned up 4 errors. I ran again with individual sticks of RAM in various slots and everything turned up fine. I've looked through the BIOS settings and everything looks fine. I've tried unplugging unnecessary pieces of hardware (other internal hard drives, CD drives, floppy, PCI cards, etc). Any help or tips on how I can even begin to troubleshoot this would be very much appreciated. Please note that i've only started playing with servers as a hobby so my knowledge wouldn't be the most refined. I'm comfortable with command line and have the initiative to know how to look up something I can't do. Unfortunately I can't seem to find any issues like this. Additionally: If a solution can't be found some assistance to write a script that will cause the server to reboot automatically if, after x minutes, it gets no response to pinging somewhere like google. Admittedly that's not the cleanest solution should my internet end up going down but I can't think of what else to do.

    Read the article

  • Ubuntu box static routing problem

    - by Rafael
    Hello, I'm trying to configure a ubuntu server to be a router. This is my interface configuration (eth2 connects to my WAN, eth0 to my LAN): auto eth2 iface eth2 inet static address 192.168.0.249 netmask 255.255.255.0 gateway 192.168.0.1 broadcast 192.168.0.255 auto eth0 iface eth0 inet static address 192.168.100.1 netmask 255.255.255.0 This is the router information: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.100.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2 0.0.0.0 192.168.0.1 0.0.0.0 UG 100 0 0 eth2 And this is dhcp configuration: subnet 192.168.100.0 netmask 255.255.255.0 { range 192.168.100.101 192.168.100.254; option domain-name-servers 201.70.86.133; option routers 192.168.100.1; authoritative; } I'm then connecting a mac os x by cable on eth0. This is en0 interface configuration: en0: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500 ether 00:26:bb:5d:82:b0 inet6 fe80::226:bbff:fe5d:82b0%en0 prefixlen 64 scopeid 0x4 inet 192.168.100.101 netmask 0xffffff00 broadcast 192.168.100.255 media: autoselect (100baseTX <full-duplex>) status: active And this is the routing table: Internet: Destination Gateway Flags Refs Use Netif Expire default 192.168.100.1 UGSc 139 32 en0 10.37.129/24 link#8 UC 2 0 vnic1 10.37.129.2 0:1c:42:0:0:9 UHLWI 0 839 lo0 10.37.129.255 ff:ff:ff:ff:ff:ff UHLWbI 0 4 vnic1 10.211.55/24 link#7 UC 2 0 vnic0 10.211.55.2 0:1c:42:0:0:8 UHLWI 0 840 lo0 10.211.55.255 ff:ff:ff:ff:ff:ff UHLWbI 0 4 vnic0 127 127.0.0.1 UCS 0 0 lo0 127.0.0.1 127.0.0.1 UH 3 507924 lo0 169.254 link#4 UCS 0 0 en0 172.16.42/24 link#10 UC 2 0 vmnet8 172.16.42.1 0:50:56:c0:0:8 UHLWI 0 839 lo0 172.16.42.255 link#10 UHLWbI 1 24 vmnet8 192.168.100 link#4 UC 2 0 en0 192.168.100.1 0:e0:7c:7e:f:99 UHLWI 139 0 en0 777 192.168.100.101 127.0.0.1 UHS 0 0 lo0 192.168.100.255 ff:ff:ff:ff:ff:ff UHLWbI 0 4 en0 192.168.116 link#9 UC 2 0 vmnet1 192.168.116.1 0:50:56:c0:0:1 UHLWI 0 839 lo0 192.168.116.255 ff:ff:ff:ff:ff:ff UHLWbI 0 4 vmnet1 When I ping 192.168.100.1, it works. When I ping 192.168.0.249, it also works. However, when I try to ping 192.168.0.1 it does not. Does anyone has any way to solve this? Is there a way to debug it? Thanks,

    Read the article

  • Aliased network interfaces and isc dhcp server

    - by Jonatan
    I have been banging my head on this for a long time now. There are many discussions on the net about this and similar problems, but none of the solutions seems to work for me. I have a Debian server with two ethernet network interfaces. One of them is connected to internet, while the other is connected to my LAN. The LAN network is 10.11.100.0 (netmask 255.255.255.0). We have some custom hardware that use network 10.4.1.0 (netmask 255.255.255.0) and we can't change that. But we need all hosts on 10.11.100.0 to be able to connect to devices on 10.4.1.0. So I added an alias for the LAN network interface so that the Debian server acts as a gateway between 10.11.100.0 and 10.4.1.0. But then the dhcp server stopped working. The log says: No subnet declaration for eth1:0 (no IPv4 addresses). ** Ignoring requests on eth1:0. If this is not what you want, please write a subnet declaration in your dhcpd.conf file for the network segment to which interface eth1:1 is attached. ** No subnet declaration for eth1:1 (no IPv4 addresses). ** Ignoring requests on eth1:1. If this is not what you want, please write a subnet declaration in your dhcpd.conf file for the network segment to which interface eth1:1 is attached. ** I had another server before, also running Debian but with the older dhcp3 server, and it worked without any problems. I've tried everything I can think of in dhcpd.conf etc, and I've also compared with the working configuration in the old server. The dhcp server need only handle devices on 10.11.100.0. Any hints? Here's all relevant config files: /etc/default/isc-dhcp-server INTERFACES="eth1" /etc/network/interfaces (I've left out eth0, that connects to the Internet, since there is no problem with that.) auto eth1:0 iface eth1:0 inet static address 10.11.100.202 netmask 255.255.255.0 auto eth1:1 iface eth1:1 inet static address 10.4.1.248 netmask 255.255.255.0 /etc/dhcp/dhcpd.conf ddns-update-style none; option domain-name "???.com"; option domain-name-servers ?.?.?.?; default-lease-time 86400; max-lease-time 604800; authorative; subnet 10.11.100.0 netmask 255.255.255.0 { option subnet-mask 255.255.255.0; pool { range 10.11.100.50 10.11.100.99; } option routers 10.11.100.102; } I have tried to add shared-network etc, but didn't manage to get that to work. I get the same error message no matter what...

    Read the article

< Previous Page | 21 22 23 24 25 26 27 28  | Next Page >