Search Results

Search found 3387 results on 136 pages for 'n layer'.

Page 103/136 | < Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >

• Disabling drop shadows around windows or the menu bar

  - by Lri

  Nocturne can disable most shadows, but only in night mode. There's an annoying flash whenever it switches to night mode. (Eg when it's launched.) Also, it doesn't remove the shadow on the menubar. Sympa at MacThemes forums has posted a .psd file with a layer that cancels out the shadow under the menu bar. However it only works if that area of the desktop picture has a low enough brightness. Applications that cover the desktop (like DeskShade) also cover the menu bar's shadow. It's not a real solution though. Unsanity's ShadowKiller stopped working in 10.5. (The website still says NOT compatible with Mac OS X 10.6 Leopard. ;)) WindowShade X doesn't have any shadow-tweaking features anymore. Being able to decrease the shadow radius would be fine as well. osx - How do I decrease the window shadow in Mac OS X? - Super User doesn't have any solutions though. No, I don't mean defaults write com.apple.screencapture disable-shadow -bool yes. This seems like something that might just be possible without any extra applications. Or at least something that other applications besides Nocturne should support. So does anyone know any better solutions?

  Read the article

• Bridging my laptop's wireless and wired adaptors

  - by stacey.richards

  I would like to be able to connect a desktop computer that does not have a wireless adapter to my wireless network. I could just run a network cable from my ADSL/wireless router to the desktop computer but sometimes this is not practical. What I would really like to do is bridge my laptop's wireless and wired adapters in such a way that I can run a network cable from my laptop to a switch and another network cable from the switch to a desktop computer so that the desktop computer can access the Internet through my ADSL/wireless router via my latop: +--------------------+ |ADSL/wireless router| +--------------------+ | +-------------------------+ |laptop's wireless adaptor| | | |laptop's wired adaptor | +-------------------------+ | +------+ |switch| +------+ | +-----------------------+ |desktop's wired adapter| +-----------------------+ A bit of Googling suggests that I can do this by bridging my laptop's wireless and wired adapters. In Windows XP's Network Connections I select both the Local Area Connection and the Wireless Network Connection, right click and select Bridge Connections. From what I gather, this (layer 2?) bridge will examine the MAC address of traffic coming from the wireless network and pass it through to the wired network if it suspects that a network adapter with that MAC address may be on the wired side, and vice-versa. If this is the case, I would assume that when the desktop computer attempts to get an IP address from a DHCP server (which is running on the ADSL/wireless router), it would send a DHCP broadcast packet which would pass through the laptop's bridge to the router and the reply would return through the laptop's bridge back to the desktop. This doesn't happen. With some more Googling I find some instruction how this can be done with Linux. I reboot to Ubuntu 9.10 and type the following: sudo apt-get install bridge-utils sudo brctl addbr br0 sudo brctl addif br0 wlan0 sudo brctl addif br0 eth0 sudo ipconfig wlan0 0.0.0.0 sudo ipconfig eth0 0.0.0.0 Once again, the desktop cannot reach the ADSL/wireless router. I suspect that I'm missing some simple important step. Can anyone shed some light on this for me?

  Read the article

• CentOS Latency High Troubleshooting

  - by Sarah Weinberger

  I have two CentOS servers connected via a 10 Gb fiber optic cable with a network emulator connected between them. All three units sit on a desk in the lab. There is also a regular 1 Gbit Ethernet cable connected to each of the machines, which provide internet connectivity. When I set the latency to something roughly below 30 ms, all is fine. When the latency gets to 70ms and above, and definitely 130ms, the network layer suspends. For instance, if I set the latency (delay) to 70ms, then launching TeamViewer (or any other application that uses network connectivity) never happens or does not work. There is no timeout message, simply no response. I have to lower to latency back down to zero to see any response and have the box start working. What is the problem and how would I go about fixing it? It seems to me some sort of setting in Linux causes one of the CentOS networking drivers to sit in an infinite loop or something. eth0 is the connection to the internet, all settings are default eth2 is the 10 Gbit fiber optic connection to the other computer with the MTU set to 9600 with all other parameters at default values.

  Read the article

• iMac 20inch (Mid 2007) SL DVD Boot Prohibitory Sign

  - by Caitlann Lloyd

  iMac 20inch (Mid 2007 Build) with Ubuntu 12.0.4 How I got in this situation I had a perfectly healthy Intel iMac running Snow Leopard several months ago. Then I got the dreaded spinning gear and several kernel panics. After getting a little frustrated (failing to find a solution online), I found an old macbook installation disk and used it to access Disk Utility. From here, I erased my entire hard drive leaving me with no OS. I then created a Ubuntu DVD and installed Ubuntu onto the system. Now, on Ubuntu, I wine installed Transmac and burned a Single layer copy (with languages, etc. removed to save space) of Snow Leopard onto a 4.7GB DVD. I tried to boot from it and was met with first the grey apple screen and a spinning cog before the grey apple shortly turned into the infamous prohibitory sign. Note: I met this problem previously when using Disk Utility to create a bootable USB of Snow Leopard, hence I severely doubt it has anything to do with the DVD created. Resources at my disposal 1 x iMac running Ubuntu 6 x 4.7GB DVDs 1 x USB Stick 12GB 1 x Windows 7 Laptop Resources I do not have Firewire cables Access to a prebuilt retail disk (Misplaced) Access to another Mac Apple Warranty I would be hugely grateful if someone was able to tell me how to install Snow Leopard again.

  Read the article

• How to make a Linux software RAID1 detect disc corruption?

  - by Paul

  This is one of the nightmare days: A virtualized server running on a Linux SW-RAID1 runs a VM that exhibits random segfaults in seemingly random codechunks. While debugging I find that a file gives different md5sums on each and every run. Digging deeper I find this: The raw disc partitions that make up the RAID1 mirror contain 2 bit-differences and ca. 9 sectors are completely empty on one disc and filled with data on the other disc. Obviously Linux gives back a sector from a undeterministically chosen disc of the mirror set. So sometimes the same sector is returned OK, sometimes the corrupted is given back. The docs say: RAID cannot and is not supposed to guard against data corruption on the media. Therefore, it doesn't make any sense either, to purposely corrupt data (using dd for example) on a disk to see how the RAID system will handle that. It is most likely (unless you corrupt the RAID superblock) that the RAID layer will never find out about the corruption, but your filesystem on the RAID device will be corrupted. Thanks. That will help me sleep. :-/ Is there a way to have Linux at least detect this corruption by using sector checksumming or something like that? Would this be detected in a RAID5 setup? Is this the moment I wish I used ZFS or btrfs (once it becomes usable without uber-admin capabilities)?

  Read the article

• Which upgrade path for disk IO bound postgres server?

  - by user41679

  Hi all, We currently have a Sun x4270 with 2xquad core Xeon Nehalmen 2.93ghz cores (16 threads), 72 gig of ram and 16 x 10k SAS disks split between the os raid 1, a partition for the Write Ahead Logs which is raid 10 and a partition for the database tables and indexes which is also raid 10, all xfs. I'm currently evaluating which path to go down in terms of upgrades. We'll be sharding the DB at some point soon, but for now I need to focus on hardware upgrades specifically. The machine is not CPU or memory bound at all at the moment, just IOWait is become an issue. The machine is mostly write access as we have a heavy caching layer. We're seeing about 300 write IOPS average on both the database partitions. We don't have any additional storage infrastructure like a Fiber Channel or ISCSI network. Budget isn't too much of a concern, something inline with the size of this server (i.e no $1m IBM machines) Space is ok on the DB side of things, we're running out obviously but there's also some reduction we can do. Additional space would be good though. My current thoughts are either: * ISCSI SAN, possible with 10Gbit network that has solid state acceleration. * FusionIO card / Sun F20 card (will the FusionIO card work in the Sun box? * DAS shelf (something like this http://www.broadberry.co.uk/das-direct-attached-storage-servers/cyberstore-224s-das) which a combination of 15k sas disks and some Intel X25-E drives for DB indexes etc) what would I need to put in the x4270 to add a DAS shelf? I think it's a SAS HBA card, do I have to use Sun's own card or will any PCI Express card work? Anything else??? what would you guys do from your experience? I appreciate it's a lot of questions, but I haven't expanded a DB machine for a number of years and the landscape has changed dramatically since then! Any advice or feedback would be very much appreciated. Let me know if there's anything else I can clarify. Thanks in advance!

  Read the article

• About to go live: virtual dedicated server or cloud?

  - by morpheous

  I am about to launch my startup company, and we will be going live in a few weeks time. We have really tight budgetary constraints, since we are bootstrapping - and would prefer not to raise external capital. I cant use shared hosting because I need more control of the server machine (for technical reasons - e.g. using proprietary extensions to PHP, Apache and in the database layer as well) - but want to control costs and dont want to go fully private server route, until we have determined the market size etc. So the only real alternatives AFAIK is between virtual server and the cloud. At the moment, cloud services seem a bit "vague" to me. My understanding is that they allow an entity to outsource its IT infrastructure, which in my mind (at least), is indistinguishable from what a hosting provider provides (at least from a functional point of view) - I would like to seek some clarification on exactly what the difference between the two is. Back to my original question, my requirements are: IT infrastructure that can scale with growth Ability to have control of the machine (for e.g. to install our internally developed libraries etc) Backup software that is flexible and comprehensive enough (yet simple to use), that allows a (secured) backup strategy to be implemented. On this issue, I have always wondered where the actual backed up data was stored (since the physical machines are remote, and one cant get access to any actual tapes etc backed onto). I would also like some advice and recommendations in this area. Regarding data size, I am expecting the dataset to be increasing by a few megabytes of data (originally, say 10Mb, in about a years time, possibly 50Mb) every day. As an aside, I have decided to deploy on a Debian server (most of my additional libraries etc were compiled and built on a Debian machine). Mindful of all of the above, I would like some advice (and reason) as to which route to take. I would also like some advice on which backup software to use, from people who have walked a similar path.

  Read the article

• Why is a SUBST'd drive inaccessible via shortcut or Run menu, but works fine from My Computer?

  - by Kev

  I have shortcuts to C:, D:, and E: in my quick launch bar. C and E work fine when I click on them, but D does nothing (that I can see) when I click on it. D and E are both SUBST'd drives pointing to folders that happen to be network shares. (I do this rather than mapping them so it doesn't have to go through the network layer--that way it works faster and I still get recycle bin functionality, etc.) If I go Start-Run and type D: or D:\, I get an error box saying This file does not have a program associated with it for performing this action. Create an association in the Folder Options control panel. If I go to My Computer and double-click the D drive, it comes up fine. Also, if I type \\servername\sharename pointing to the same place, it comes up fine. This just started happening this morning, out of the blue. It has been working fine ever since I set it up. Why might this be?

  Read the article

• Exchange 2010 CAS Removal == Broken???

  - by Doug

  Hi there, I recently upgraded to exchange 2010 and have a setup with 2 of my servers running CAS roles - EXCH01, EXCH02 EXCH02 just happens to also have a mailbox role where a lot of the users sit EXCH01 is my front facing CAS server, and is facing the net with SSL etc and incoming mail moving through it as a hub transport layer server as well. As i was trying to lean things out in my VM environment i removed the CAS role from EXCH02 and all hell broke loose. All the mail users that have a mailbox on EXCH02 had their homeMTA set to a deleted items folder in AD and so did their msExchHomeServer properties. After a complete battle i manually fixed these issues to the oldvalues, and in the mean time reinstalled CAS on EXCH02 (management was going nuts with out OUTLOOK working so i just put things back the way they were in a hurry.) I must add as a strange thing on the side, that before i reset these to point at EXCH02 i tried EXCH01 and it failed. I still want to remove the CAS role from EXCH02 as it should really not have it (error on install/planning on my part) and would have thought that this would not cause the issues it did, i assumed that the fact that there was another CAS server in the admin group all would be good. Was i wrong in my assumption? and what can i do to complete this successfully the second time round? Do i need to rehome all the mailboxes to the CAS server? is this a bug in the role uninstall?

  Read the article

• This .mpg video clip doesn't play well

  - by Roey

  I've installed K-lite mega codec pack v6.9.0 with playback essentials without player. My default and only media player is windows media player. here are the clip's media info: General Complete name : D:\Users\Roey\Downloads\B384MV.mpg Format : MPEG-PS File size : 273 MiB Duration : 4mn 59s Overall bit rate : 7 643 Kbps Video ID : 224 (0xE0) Format : MPEG Video Format version : Version 2 Format profile : Main@High Format settings, BVOP : No Format settings, Matrix : Default Format settings, GOP : M=1, N=15 Duration : 4mn 57s Bit rate mode : Variable Bit rate : 7 363 Kbps Nominal bit rate : 9 000 Kbps Width : 1 920 pixels Height : 1 080 pixels Display aspect ratio : 16:9 Frame rate : 25.000 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Compression mode : Lossy Bits/(Pixel*Frame) : 0.142 Stream size : 261 MiB (96%) Audio ID : 192 (0xC0) Format : MPEG Audio Format version : Version 1 Format profile : Layer 3 Mode : Joint stereo Duration : 4mn 59s Bit rate mode : Constant Bit rate : 128 Kbps Channel(s) : 2 channels Sampling rate : 44.1 KHz Compression mode : Lossy Stream size : 4.56 MiB (2%) Menu When I play it there is no sound (just a little "kahhhh" noise every 10-20 seconds) and the frames are moving very slow - it "jumps" frames. A blue tray icon [FFa] "ffdshow audio decoder" pops with the following details: Input:MP3, stereo, 44100 Hz (libavocodec) Output:PCM, stereo, 44100 Hz, 16-bit integer Any help will be much appreciated. Thanks

  Read the article

• kvm-over-ip, multiple machines per cable run

  - by Sirex

  I'm looking at getting a kvm-over-ip setup for a server room. Typically these devices have 16 or so cat5 leads that come out of them and then a convertor that converts each cat5 into a vga & ps2 pair. Can you run one cable from the unit into a switch, and then leads from the switch into each machine ? I have several machines on the other side of the server room that i'd like to have avaliable but i dont want to run 16 cables to them. I'm thinking this should be possible being IP layer and all, but as each device normally has its own cable out the back of the kvm unit i'm not certain. Perhaps the kvm's rear ports act essentially like a switch anyway in which case it should work, or perhaps if i run all 16 cables into a seperate switch right next to it and aggregate the ports together, run one cable to a switch on the other side of the room with similar number of ports agregated together, then use that switch to plug each macine into ? I'm fairly sure this is possible, but i just want to check before i shell out the cash as i've never tried it.

  Read the article

• User authentication -- username mismatch in IIS in ASP.NET application

  - by Cory Larson

  Last week, an employee's Active Directory username was changed (or a new one was created for them). For the purposes of this example, let's assume these usernames: Old: Domain\11111 New: Domain\22222 When this user now logs in using their new username, and attempts to browse to any one of a number of ASP.NET applications using only Windows Authentication (no Anonymous enabled), the system authenticates but our next layer of database-driven permissions prevents them from being authorized. We tracked it down to a mismatch of usernames between their logon account and who IIS thinks they are. Below are the outputs of several ASP.NET variables from apps running in a Windows 2008 IIS7.5 environment: Request.ServerVariables["AUTH_TYPE"]: Negotiate Request.ServerVariables["AUTH_USER"]: Domain\11111 Request.ServerVariables["LOGON_USER"]: Domain\22222 Request.ServerVariables["REMOTE_USER"]: Domain\11111 HttpContext.Current.User.Identity.Name: Domain\11111 System.Threading.Thread.CurrentPrincipal.Identity.Name: Domain\11111 From the above, I can see that only the LOGON_USER server variable has the correct value, which is the account the user used to log on to their machine. However, we use the "AUTH_USER" variable for looking up the database permissions. In a separate testing environment (completely different server: Windows 2003, IIS6), all of the above variables show "Domain\22222". So this seems to be a server-specific issue, like the credentials are somehow getting cached either on their machine or on the server (the former seems more plausible). So the question is: how do I confirm whether it's the user's machine or the server that is botching the request? How should I go about fixing this? I looked at the following two resources and will be giving the first one a try shortly: http://www.interworks.com/blogs/jvalente/2010/02/02/removing-saved-credentials-passwords-windows-xp-windows-vista-or-windows-7 http://stackoverflow.com/questions/2325005/classic-asp-request-servervariableslogon-user-returning-wrong-username/5299080#5299080 Thanks.

  Read the article

• Transferring an SQL Processor License to a virtual hosted environment

  - by Andrew Shepherd

  My company is currently hosting a service in-house, and we want to move to an externally hosted environment. We would then be using a virtual server. I understand that this might be spread across multiple machines, but from my perspective as a customer, this layer is abstracted away - I shouldn't know or care about the hardware that the OS is hosted on. We have a licensed edition of SQL Server 2008. This is one Processor license. Will it be a violation of the licensing agreement to use this in a virtual environment. From the reference guide here it says When licensed Per Processor With Workgroup, Web, and Standard editions, for each server to which you have assigned the required number of per processor licenses, you may run, at any one time, any number of instances of the server software in physical and virtual operating system environments on the licensed server. However, the total number of physical and virtual processors used by those operating system environments cannot exceed the number of software licenses assigned to that server For enterprise edition there is an added option: if all physical processors in a machine have been licensed, then you may run unlimited instances of SQL server 2008 in one physical and an unlimited number of virtual operating environments on that same machine. I'm having trouble getting my head around this. Would I theoretically have to get a license for every processor in this virtual environment (which is effectively impossible because I have no way of knowing how many processors there actually are)? Or can I just say that it's hosted on one "virtual" server, so that's OK?

  Read the article

• Simple way to set up port knocking on Linux?

  - by Ace Paus

  There are well known benefits of Port Knocking utilities when utilized in combination with firewall IP table modification. Port Knocking is best used to provide an additional layer of security over other tools such as the OpenSSH server. I would like some help setting it up on a ubuntu server. I looked at some port knocking implementations here: PORTKNOCKING - A system for stealthy authentication across closed ports. IMPLEMENTATIONS http://www.portknocking.org/view/implementations fwknop looked good. I found an Android client here. And fwknop (both client and server) is in the ubuntu repos. Unfortunately, setting it up (on the server) looks difficult. I do not have iptables set up. My proficiency with iptables is limited (but I understand the basics). I'm looking for a series of simple steps to set it up. I only want to open the SSH port in response to a valid knock. Alternatively, I would consider other port knocking implementations, if they are much simpler to set up and the desired Linux and Android clients are available.

  Read the article

• SQL Server Read Locking behavior

  - by Charles Bretana

  When SQL Server Books online says that "Shared (S) locks on a resource are released as soon as the read operation completes, unless the transaction isolation level is set to repeatable read or higher, or a locking hint is used to retain the shared (S) locks for the duration of the transaction." Assuming we're talking about a row-level lock, with no explicit transaction, at default isolation level (Read Committed), what does "read operation" refer to? The reading of a single row of data? The reading of a single 8k IO Page ? or until the the complete Select statement in which the lock was created has finished executing, no matter how many other rows are involved? NOTE: The reason I need to know this is we have a several second read-only select statement generated by a data layer web service, which creates page-level shared read locks, generating a deadlock due to conflicting with row-level exclusive update locks from a replication prcoess that keeps the server updated. The select statement is fairly large, with many sub-selects, and one DBA is proposing that we rewrite it to break it up into multiple smaller statements (shorter running pieces), "to cut down on how long the locks are held". As this assumes that the shared read locks are held till the complete select statement has finished, if that is wrong (if locks are released when the row, or the page is read) then that approach would have no effect whatsoever....

  Read the article

• Router vs switch in a LAN [closed]

  - by servernewbie

  If I have a LAN and and connect it with a switch, I understand it uses a CAM table to route packets in layer 2 (by saving mac to port relations). So far all good. However, when using a router for a LAN (ONLY for a LAN, not to connect it to "the outside" WAN/internet/etc) I get a bit confused as to how it internally processes packets. I would first split this into two router scenarios: Router with buit-in switch In this scenario, I would expect that it will act exactly as a switch with a CAM table internally. This would probably benefit a bit in speed (guessing here?) compared to the next option. Router without built-in switch Here is where I get confused. If hostA wants to send a packet to hostB, it will ARP to find hostB's MAC address and send it there. Now, if we had a switch (above scenario) this would be easy. But how does it work now in a router WITHOUT a switch? If I would guess, hostA would send an Ethernet frame with hostB's MAC address to the line. The router would fetch the packet (even though the router has another MAC address, it would still fetch this packet even if it only contains hostB's MAC address). It would strip the Ethernet frame header and check the IP, and then check its own internal ARP table again for the MAC address. Now, this would seem like a waste of resources compared to a router with a built-in switch. But maybe it does not work like that at all. Does it also contain a CAM table? If that would be true, what would then the difference between these two routers really be?

  Read the article

• ProCurve ACL to prevent a subnet from leaving the switch

  - by kce

  I have a single HP ProCurve 2610 in a remote location that is connected in with the rest of the network via SHDSL. There are two Layer-3 networks on this segment. ACLs are setup to deny one subnet (192.0.2.0/24) from ever being able to leave the switch by virtue of being applied to port attached to the upstream connection. The other subnet should be permitted to freely leave the switch. Both subnets are on the same VLAN. Unfortunately SFlow very clearly show broadcast traffic from 192.0.2.0/24 on the upstream connection. ProCurve ACLs are not my strong suit but I feel like I'm missing something very simple here. ip access-list extended "Filter for Camera Network" deny ip 192.0.2.0 0.0.0.255 0.0.0.0 255.255.255.255 log permit ip 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.255 exit interface 24 name "DSL - UPLINK" access-group "Filter for Camera Network" in exit Unless I am mistaken traffic from 192.0.2.0/24 should be dropped as it crosses the uplink port (int 24) whereas all other traffic will be permited by the following default allow rule. What exactly am I missing here? EDIT: Firstly, why do you have two subnets contained in the same VLAN? Because that's how it was configured by a previous administrator and while it makes conceptual sense that a single subnet is "mapped" to a single VLAN there's no technical constraint that I am aware of that makes this have to be the case. Instead of filtering inbound traffic on your uplink, you should be filtering outbound traffic. The HP2600 series can only filter inbound traffic on interfaces. Should I change my filter to deny any to 192.0.2.0/24?

  Read the article

• Multiple servers vs 1 big server performace

  - by pistacchio

  Hi to all! My team of developers has suggested a server structure for an upcoming project we are developing. Our structure is "logical", meaning that the various logical components of the application (it is a distributed one) relies on different servers. Some components are more critical than others and will be subjected to more load. Our proposal was to have 1 server per component but the hardware guys suggested to replace the various machines with a single, bigger one with virtual servers. They're gonna use Blade Servers. Now, I'm not an expert at all, but my question to the guys was: so if we need, for example, 3 2GHz CPU / 2GB RAM machines and you give me 1 machine with 3 2GHz CPUs and 6 GB of RAM it is the same? They told me it is. Is this accurate? What are the advantages or disadvantages of both the solutions? What are the generally accepted best practices? Could you point out some URL reference dealing with the problem? Thank you in advance! EDIT: Some more info. The (internet / intranet) application is already layered. We have some servers on the DMZ that will expose pages to the internet and the databases are on their own machines. What we want to split (and they want to join) are some webservers that mainly expose webservices. One is a DAL that communicates with the database layer, one is our Single Sign On / User Profile application that gets called once per page and one is a clone of what seen on the Internet to be used on our lan.

  Read the article

• Distributed storage and computing

  - by Tim van Elteren

  Dear Serverfault community, After researching a number of distributed file systems for deployment in a production environment with the main purpose of performing both batch and real-time distributed computing I've identified the following list as potential candidates, mainly on maturity, license and support: Ceph Lustre GlusterFS HDFS FhGFS MooseFS XtreemFS The key properties that our system should exhibit: an open source, liberally licensed, yet production ready, e.g. a mature, reliable, community and commercially supported solution; ability to run on commodity hardware, preferably be designed for it; provide high availability of the data with the most focus on reads; high scalability, so operation over multiple data centres, possibly on a global scale; removal of single points of failure with the use of replication and distribution of (meta-)data, e.g. provide fault-tolerance. The sensitivity points that were identified, and resulted in the following questions, are: transparency to the processing layer / application with respect to data locality, e.g. know where data is physically located on a server level, mainly for resource allocation and fast processing, high performance, how can this be accomplished? Do you from experience know what solutions provide this transparency and to what extent? posix compliance, or conformance, is mentioned on the wiki pages of most of the above listed solutions. The question here mainly is, how relevant is support for the posix standard? Hadoop for example isn't posix compliant by design, what are the pro's and con's? what about the difference between synchronous and asynchronous opeartion of a distributed file system. Though a synchronous distributed file system has the preference because of reliability it also imposes certain limitations with respect to scalability. What would be, from your expertise, the way to go on this? I'm looking forward to your replies. Thanks in advance! :) With kind regards, Tim van Elteren

  Read the article

• Switch Before Firewall / Router - Multiple public IPs

  - by rii

  I currently Have a 10Mbit Full duplex circuit connected to a small unmanaged switch which then connects to a Sonicwall Firewall / Router. I have several public IP addresses (/28) that are assigned to several devices in my setup. Now the problem is the small switch I have was lent to me and needs to be returned, I have replaced this switch with several other switches but for some reason any other switch I use causes the network to become extremely slow. I believe this is a problem with the autonegotiation of theses hubs, so I am thinking of purchasing a small managed switch (cisco 300 series) and making the receiving port on the swith Explicitly 10Mbit Full Duplex and see if this works. My question is, being that this is a managed switch and needs an IP, will I still be able to run my public ips through it? Say the circuit has 70.80.4.1 - 7 will I still be able to assign 70.80.4.2 to my firewall and 70.80.4.3 to my router connected to some other port in the switch? Will I have to assign the switch a public IP address in this range as well for it to "route" to those other devices or does the switch does not care what IPs goes through it while operating as a Layer 2 Switch? Any help would be greatly appreciated. Thanks in advanced!

  Read the article

• Why Would one VLAN have no Communication on one Switch?

  - by Webs

  So the problem is we have a device or host that needs to communicate on a specific VLAN. This VLAN is not new, it is running all throughout our environment and works fine. But the VLAN was recently configured on the switch in question, a Cisco 3750. The DHCP server is handing out addresses on that VLAN with no problem. I have verified the cable between the host and switch and tried multiple hosts, but none of them can communicate or get an address. I plugged my laptop into an empty port which had a different VLAN assigned and immediately got a DHCP address. When I changed that port to the same VLAN I'm having issues with I got the same problem. The laptop just sits there and tries to DHCP an address but nothing happens. I double checked the cores and their Layer 3 VLAN config and its fine too. Plus I figured the issue couldn't be with them because the VLAN works fine everywhere else it exists. So the only other thing I can think of is the switch, but the VLAN exists on the switch and seems to be configured correctly. The trunks appear to be configured just fine as well too. Anyone have any ideas? I'm lost on this one.

  Read the article

• To what extent is size a factor in SSD performance?

  - by artif

  To what extent is the size of an SSD a factor in its performance? In my mind, correct me if I'm wrong, a bigger SSD should be, everything else being equal, faster than a smaller one. A bigger SSD would have more erase blocks and thus more leeway for the FTL (flash translation layer) to do garbage collection optimization. Also there would be more time before TRIM became necessary. I see on Wikipedia that it remarks that "The performance of the SSD can scale with the number of parallel NAND flash chips used in the device" so it seems throughput also increases significantly. Also many SSDs contain internal caches of some sort and presumably those caches are larger for correspondingly large SSDs. But supposing this effect exists, I would like a quantitative analysis. Does throughput increase linearly? How much is garbage collection impacted, if at all? Does latency stay the same? And so on. Would the performance of a 8 GB SSD be significantly different from, for example, an 80 GB SSD assuming both used high quality chips, controllers, etc? Are there any resources (webpages, research papers, presentations, books, etc) that discuss correlations between SSD performance (4 KB random write speed, latency, maximum sequential throughput, etc) and size? I realize this does not really sound like a programming question but it is relevant for what I'm working on (using flash for caching hard drive data) which does involve programming. If there is a better place to ask this question, eg a more hardware oriented site, what would that be? Something like the equivalent of stack overflow (or perhaps a forum) for in-depth questions on hardware interfaces, internals, etc would be appreciated.

  Read the article

• Steps to deploy a custom routing protocol

  - by user134589

  I'm a Ph.D Student and I'm researching a Service Centric Networking architecture with resourceallocation on a large scale. What I'm looking to do is expand an existing routing protocol like OSPF with extra fields and some new message types that I need for communication between Nodes. I want to manipulate the cost of a network link and I want paths to be calculated like in OSPF V2/v3, but using the cost that my algorithms have calculated. What I have I have the source code of OSPF from Quagga. I am assuming I can edit this code how I want, including packet structures and creating new types. Yes, I am aware it won't be easy but this is a 6 years research project and I am eager to develop something new, to move forward. What I need I would like to know how I can deploy the edited OSPF source files I have (written in C) on any type of server. I have a large testbed environment available with hundreds of virtual nodes and pretty much any OS out there. So if I want to test my extended protocol, how do I make all the nodes in a network use this to communicate? I do not understand what parts of the kernel I need to edit here. I tried searching for days now and I am unable to find how to deploy a non-existing routing protocol, without the use of an application-level framework. If somebody could push me in the right direction that'd be awesome. note: I need this to be a routingprotocol and not an application, since I want this to work on op of the network layer for performance reasons. Thanks!

  Read the article

• Having two IP Routes/Gateways of last Resort on an HP Switch

  - by SteadH

  We have an HP Layer 3 Switch that is doing IP routing between vlans. The general set up is that the switch has an IP address on each VLAN and IP routing is enabled. On our servers VLAN, we have a firewall that has a connection to the outside world. To set a IP route on the HP router, we use IOS command ip route 0.0.0.0 0.0.0.0 192.168.2.1 where 192.168.2.1 is the address of our firewall, and the zeros essentially mean to route all traffic that the switch doesn't know what to do with out the firewall as a gateway. We're in the middle of an ISP and firewall change. I set up the new firewall and ran the IOS command ip route 0.0.0.0 0.0.0.0 192.168.2.254 (the address of the new firewall). Things started working nicely. When I reviewed the configuration of the switch though, I noticed that it did not replace the previous ip route command, but just added another route. Now, I know how to remove the old firewall route (no ip route 0.0.0.0 0.0.0.0 192.168.2.1), but what is the effect of having these two 0.0.0.0 routes? Is it switch implosion? Will a server just respond back over the route it receives the request from? I've read elsewhere that having two default gateways is an impossibility by definition, but I'm curious about this situation that our switch allowed. Thanks!

  Read the article

• How does rsync --daemon know which way it is being run?

  - by Skaperen

  I am wanting to run rsync over an SSL/TLS encrypted connection. It does not do this directly so I am exploring options. The stunnel program looks promising, although more complicated than designed due to the need to hop connections with the -r option. However, I do find there is a -l option to run a program. I am assuming this works by having two processes, one to carry out the SSL/TLS work, and one to be the worker which the client is communicating to. These would then communicate by a pipe pair or two way socket between them. What struck me as odd when I surveyed a number of web pages to see how to properly set this up is that whether running as a standalone daemon, or under a super daemon like inetd, the arguments for rsync are the same. How does rsync --daemon know whether it should open a socket and listen on it for many connections, or just service one connection by communicating with the stdin/stdout descriptors is has when it starts up (which really would go through the extra process to handle the encryption, description, and SSL/TLS protocol layer)? And then I need to find a way to wrap the client to have it do SSL/TLS in one simple command (as opposed to connection hopping that stunnel seems to favor).

  Read the article

< Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >