Search Results

Search found 19557 results on 783 pages for 'networking programming'.

Page 13/783 | < Previous Page | 9 10 11 12 13 14 15 16 17 18 19 20  | Next Page >

  • Xen networking is inconsistent in multiple ways

    - by WildVelociraptor
    I've been running xen for a few weeks now on an Ubuntu 12.04 server. I've got 3 guests: a Windows Server 2003 guest, an Ubuntu guest, and a Windows 7 Guest. My Server 2003 guest seems to work fine; I can ping it from the network, the hostname resolves correctly, and it can see the internet. This guest is attached to xenbr0, and its IP is 10.100.1.21. My Win7 guest is what is driving me crazy. I use the same configuration script as a base, changing the important parts (hostname and boot disk, mainly). It installed correctly, and is currently running, but I am unable to ping this guest. It's hostname is "alexander", with an IP of 10.100.1.22. It is also using xenbr0. The guest can ping the firewall and various IP addressess, but seems unable to resolve hostnames. Now heres the weird part: when I use rdesktop (RDP client) from my laptop (not the xen host) to connect to alexander, it works just fine. It apparently resolves the hostname fine, and does the same with the IP address. So, can someone tell me why I can access this guest using RDP, but not using ping, nslookup, traceroute, etc? It's apparently invisible to all but RDP. Also, is it okay to use two guests on the same bridge, or do i need different ones for each guest? Thanks in advance for any help. Regards

    Read the article

  • VMware networking - PortChannel or not?

    - by dunxd
    My ESX hosts each have 8 NICS. I have set up 2 NICs for our iSCSI SAN - each is connected to a different SAN switch. 2 NICs are set up for vMotion and Service Console - these are each connected to a different core switch (ports are trunked with VLANs dedicated to vMotion and Management) I now have four ports left over. Currently we have these set up each going into our default VLAN. Two NICs are connected to one core-switch and two are connected to the other. We decided to aggregate the connections to each switch - so they are teamed at the vswitch end, and port channelled at the physical switch end. I am now reading that port channelling these connections is not particularly useful, perhaps even over complicating things. Is there a particular problem with using port channels for VMware? What method provides the best balance between redundancy and performance?

    Read the article

  • Hyper-V Virtual Machine Networking issues related to Max Ethernet Frame Size

    - by Goatmale
    I fixed an issue today earlier today but i'm interested in learning WHY it worked. We set up a new Hyper-V virtual machine only to discover that HTTP traffic wasn't working. HTTPS, pings, everything else was working fine. After months of prodding around I took a shot in the dark. On the Hyper-V host server, the physical NIC card had an advanced setting of "Max Ethernet Frame Size" set to 1500. After setting this setting to 1514 the issue was fixed. Alternatively, setting this to 1512 did not solve the issue; 1514 is the magic number. My best guess it that when this setting was set to 1500 it was allowing incoming pings because the data payload was a lot smaller of say, HTTP traffic. As far as HTTPS traffic, I read about something called "Path MTU discovery" which i'm going to assume why is HTTPs traffic was getting through fine, albeit slower. Looking at this post, people agree that 1518 is the max total frame size. Why didn't I need to change this to 1518 instead of 1514 bytes? Why is the default frame size 1500 if that's the max size of the Ethernet payload and not the max size.

    Read the article

  • dead man's switch for remote networking interventions

    - by ascobol
    Hi, As I'm going to change the network configuration of a remote server, I was thinking of some security mechanisms to protect me from accidentally loosing control on the server. The level-0 protection I'm using is a scheduled system reboot: # at now+x minutes > reboot > ctrl+D where x is the delay before reboot. While this works relatevly well for very simple tasks like playing with iptables this method has at least two drawbacks: It's not very reactive, ie a connectivity problem should be detected automatically if for example an automatic remote ssh command fails does not work anymore for x seconds. It can obviously not work if one need to modify some configuration files and then reboot to test the changes. Are you guys using some tool for the second point ? I would love to have something able to revert the system configuration in a previously known stable state if I can't join the server X minutes after reboot. Thanks!

    Read the article

  • Networking problems in VMWare with wireless bridge

    - by Robert Koritnik
    Barebone data: virtualization: VMWare Workstation 6.5 (latest) Host: Windows Server 2008 x64 Guest: Windows Server 2008 x86 Host network adapter: Ethernet (see comment) Host network adapter: Wireless (see comment) Guest ethernet network adapter 1: Bridged VMNet (automatic) Guest ethernet network adapter 2: Host only VMNet comment: my host has LAN and Wifi but only one at the same time. I'm either wired or wireless. Never both. So bridged connection on VM goes either via wire or air. Problem When I'm wirelessly connected on the host and I access internet within VM my connection just gets stalled (not dropped). It doesn't experience any timeout whatsoever, it just stops downloading/communicating. For instance: I start downloading a file with a browser (IE/FF/CR doesn't matter) and I have to pause/restart download when speed drops to 0. I could wait indefinitely but connection won't pick-up automatically. What did I miss in my network configuration? Update 1 I've tested this in various combinations. This works fine when host is connected via Ethernet. But when host is connected via Wifi, the connection on the guest works as previously described. It connects fine. It gets a valid IP from DHCP... Everything is cool as long as you don't start doing some intensive network traffic (ie. download a 2MB file) In this case it starts downloading and stops after a while. Speed just drops to 0B/s... Sometimes it picks up back, sometimes it doesn't. Connection still stays and works. I can ping around with no problem.

    Read the article

  • ping/ssh networking problem with server from 1 particular windows xp laptop

    - by user47650
    I am experiencing an odd problem with one specific server at my data centre connecting from my laptop. Basically the server is accessible from other machines in my house, but not from 1 particular laptop which is running windows XP. I have setup tcpdump on the server and wireshark on the laptop, and I can see ping echo request and reply packets that actually make it back to the wireshark on the laptop, but nothing shows in the ping console output like so; $ ping xxx.55.32.255 Pinging xxx.55.32.255 with 32 bytes of data: Request timed out. Request timed out. Request timed out. Request timed out. Ping statistics for xxx.55.32.255: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), But I can see from the wireshark on my local laptop that the ping reply gets back... No. Time Source Destination Protocol Info 46 3.964474 192.168.1.64 xxx.55.32.255 ICMP Echo (ping) request Frame 46 (74 bytes on wire, 74 bytes captured) Ethernet II, Src: Intel_31:d3:01 (00:19:d2:42:c3:01), Dst: ThomsonT_01:b8:2c (00:14:7f:02:b9:3c) Internet Protocol, Src: 192.168.1.64 (192.168.1.64), Dst: xxx.55.32.255 (xxx.55.32.255) Internet Control Message Protocol No. Time Source Destination Protocol Info 48 4.119060 xxx.55.32.255 192.168.1.64 ICMP Echo (ping) reply Frame 48 (74 bytes on wire, 74 bytes captured) Ethernet II, Src: ThomsonT_01:b8:2c (00:14:7f:01:b8:2c), Dst: Intel_21:c3:01 (10:20:d2:31:c3:01) Internet Protocol, Src: xxx.55.32.255 (xxx.55.32.255), Dst: 192.168.1.64 (192.168.1.64) Internet Control Message Protocol obviously I have disabled the windows firewall and there is nothing in the windows event log. There is nothing else obviously strange about the server as it is the same build as other servers that I can connect to fine.

    Read the article

  • networking tunnel adapter connections?

    - by Karthik Balaguru
    I understand that Tunnel Adapter LAN is for encapsulating IPv6 packets with an IPv4 header so that they can be sent across an IPv4 network. Few queries popped up in my mind based on this :- If i do 'ipconfig', Apart from ethernet adapter LAN details, I get a series of statments as below - Tunnel adapter Local Area Connection* 6 Tunnel adapter Local Area Connection* 7 Tunnel adapter Local Area Connection* 12 Tunnel adapter Local Area Connection* 13 Tunnel adapter Local Area Connection* 14 Tunnel adapter Local Area Connection* 15 Tunnel adapter Local Area Connection* 16 Except for the *16, all the other Tunnel Adapter Local Area Connections show Media Disconnected. Why is the numbering for the Tunnel adapter LAN not sequential? It is like 6, 7, 12, 13, 14, 15, 16. A strange numbering scheme! I tried to figure it out by thinking of some arithmetic series. But, it does not seem to fit in. There is a huge gap between 7 and 12. Any ideas? What is the need for so many Tunnel Adapter LAN connections? Can you tell me a scenario that requires all of those ? I did ipconfig /all to get more information. From the listing, I understand that: 16, 15, 14, 12 are Microsoft 6to4 Adapters 13, 6 are isatap Adapters 7 is Teredo Tunneling Pseudo-interface I understand that the above are for automatic tunneling so that the tunnel endpoints are determined automatically by the routing infrastructure. 6to4 is recommended by RFC3056 for automatic tunneling that uses protocol 41 for encapsulation. It is typically used when an end-user wants to connect to the IPv6 Internet using their existing IPv4 connection. Teredo is an automatic tunneling technique that uses UDP encapsulation across multiple NATs. That is, It is to grant IPv6 connectivity to nodes that are located behind IPv6-unaware NAT devices ISATAP treats the IPv4 network as a virtual IPv6 local link, with mappings from each IPv4 address to a link-local IPv6 address. That is to transmit IPv6 packets between dual-stack nodes on top of an IPv4 network. That is, to put in simple words, ISATAP is an intra-site mechanism, while the 6to4 and Teredo are for inter-site tunnelling mechanisms. It seems that Teredo should alone enabled by default in Vista, But my system does not show it to be enabled by default. Interestingly, it shows a 6to4 tunnel adapter (Tunnel adapter LAN connection 16) to be enabled by default? Any specific reasons for it? If i do ipconfig /all, why is only one Teredo present while four 6to4 are present ? I searched the internet for answers to the above queries, but I am unable to find clear answers.

    Read the article

  • MIDI Over Networking on OSX: Lots of beachballing

    - by Yar
    I have 4 computers connected to a Wifi router (with no Internet uplink). Whenever we enter the Network interface for Audio/Midi preferences in ANY of the computers, the Mac beachballs and then finally finds its way. Occasionally, however, one of the computers fails to receive the MIDI information that was destined for it via the Network MIDI interface. Changing to all wired connections does NOT help. Adding Internet uplink DOES help and the problem is resolved. This makes no sense to me as the computers can access each other just fine with or without the Internet uplink. Any ideas? [NOTE: I'll update the question if people correct my terminology, or feel free to do that if you have the rights].

    Read the article

  • Networking switch setup

    - by Crash893
    I have two 48 port gigabit netgear switches with 2 SFP ports each (i also have two Mini-GBIC copper transceiver modules) Is it best to set the ports up by using the built in ports (ie plug port 1 of switchB into port 48 of switchA and port1 of switchA into the router) or is there an advantage to using the mini-gbic? (lets call the sfp ports 49 and 50) router - port 49 on switchA, port 50 switchA - port 49 SwitchB

    Read the article

  • Samba networking with a domain-joined computer

    - by MCS
    I have two computers connected to the same linksys router - one running Ubuntu 8.04 and one running Windows 7. The Windows computer is part of a work domain (when connected via VPN). I'm trying to also create a home network so I can access the linux server from Windows. From what I understand, I have to first create a Windows workgroup and then configure Samba on linux to join the Windows network. So in Windows, I went to Control Panel - Network and Internet - HomeGroup and got the following message: There is currently no homegroup on your network. Because this computer also belongs to a domain, you can't create your own homegroup, but can join one created by someone on your network. Can I use Samba to create a homegroup? Is there any other way to create a Windows workgroup? Or am I barking up the wrong tree completely?

    Read the article

  • Very strange networking problem in all computers in my house

    - by Anthony
    I have three computers in my house: One desktop (wired), and two laptops (wireless). I'm using Cox Communications (yes they suck), and yesterday they had a major outage. I know it was them because I called them up when I started losing connection to the internet. All the computers can connect just fine, but they don't have internet access. It just says "local only". The weird thing is, some of them work occasionally. For the first day my laptop was working perfectly, while all the other computers couldn't connect. Later on in the day it got reversed, and the desktop was the one with internet access. By the second day the problem on Cox's end was fixed, but we still had no access. I called them up and they reset my modem, and did the usual troubleshooting stuff. It never fixed the problem, but we found out that the problem had to do with conflicting IP addresses. My router was a Linksys WRT54G and it was about 5 years old. I figured it might have gotten damaged from the outage since it was so old, and now it's having trouble "fixing itself" and giving out the proper IP addresses. So I bought a new router, a Cisco Linksys E1000. I set everything up, and still the same problem. My computer has access right now (that's how I'm writing this), but no other computers seem to be able to get access. Is there possible damage to the modem? Can someone help me please? Sorry for this being so long.

    Read the article

  • Windows 7 and XP Networking

    - by David-Zazeski
    I'm trying to setup a home network between a windows 7 and windows xp machine. I have a small hub. My XP computer has a manually assigned IP address (192.168.0.10) and I set my Windows 7 machine to have a manually assigned IP address (192.168.0.15). The XP computer works, but the Windows 7 machine does not see the network. It says that there is no connectivity. Ping does not work from either machine. Does anyone have any suggestions?

    Read the article

  • Networking Mac and PC - Firewall Issue?

    - by zm15
    Here's the scenario: Work network - I have a Mac and a PC - OS X is Snow Leopard - Windows 7 I am trying to connect to the PC from the Mac. IT ONLY works if I turn off the firewall in Windows. I tried to trace the port and connection it was using, it appears to be on port 445 via TCP. I really prefer not to leave this open, or is it OK? How can I only allow this connection while still leaving the firewall on?

    Read the article

  • networking tunnel adapter connections?

    - by Karthik Balaguru
    I understand that Tunnel Adapter LAN is for encapsulating IPv6 packets with an IPv4 header so that they can be sent across an IPv4 network. Few queries popped up in my mind based on this :- If i do 'ipconfig', Apart from ethernet adapter LAN details, I get a series of statments as below - Tunnel adapter Local Area Connection* 6 Tunnel adapter Local Area Connection* 7 Tunnel adapter Local Area Connection* 12 Tunnel adapter Local Area Connection* 13 Tunnel adapter Local Area Connection* 14 Tunnel adapter Local Area Connection* 15 Tunnel adapter Local Area Connection* 16 Except for the *16, all the other Tunnel Adapter Local Area Connections show Media Disconnected. Why is the numbering for the Tunnel adapter LAN not sequential? It is like 6, 7, 12, 13, 14, 15, 16. A strange numbering scheme! I tried to figure it out by thinking of some arithmetic series. But, it does not seem to fit in. There is a huge gap between 7 and 12. Any ideas? What is the need for so many Tunnel Adapter LAN connections? Can you tell me a scenario that requires all of those ? I did ipconfig /all to get more information. From the listing, I understand that: 16, 15, 14, 12 are Microsoft 6to4 Adapters 13, 6 are isatap Adapters 7 is Teredo Tunneling Pseudo-interface I understand that the above are for automatic tunneling so that the tunnel endpoints are determined automatically by the routing infrastructure. 6to4 is recommended by RFC3056 for automatic tunneling that uses protocol 41 for encapsulation. It is typically used when an end-user wants to connect to the IPv6 Internet using their existing IPv4 connection. Teredo is an automatic tunneling technique that uses UDP encapsulation across multiple NATs. That is, It is to grant IPv6 connectivity to nodes that are located behind IPv6-unaware NAT devices ISATAP treats the IPv4 network as a virtual IPv6 local link, with mappings from each IPv4 address to a link-local IPv6 address. That is to transmit IPv6 packets between dual-stack nodes on top of an IPv4 network. That is, to put in simple words, ISATAP is an intra-site mechanism, while the 6to4 and Teredo are for inter-site tunnelling mechanisms. It seems that Teredo should alone enabled by default in Vista, But my system does not show it to be enabled by default. Interestingly, it shows a 6to4 tunnel adapter (Tunnel adapter LAN connection 16) to be enabled by default? Any specific reasons for it? If i do ipconfig /all, why is only one Teredo present while four 6to4 are present ? I searched the internet for answers to the above queries, but I am unable to find clear answers.

    Read the article

  • Windows 7 Networking Problem

    - by bstorrie
    Hello, I'm on a Windows 7 Computer with an additional Win7 computer and an XP computer and I keep getting an error: 0x8007046a: "Not enough server storage is available to process this command" when I try to connect to a share on the Windows XP Computer. The Windows 7 Computers talk fine as far as HomeGroup, etc, but no dice with XP shares. Additionally this is in a workgroup. I have searched countless forums including TechNet, tried IRPStackSize, DhcpNodeType, and Uninstalling/Reinstalling File and Printer Sharing for M$ Networks. Any help is much appreciated.

    Read the article

  • Optimal Networking Setup for a 2-Story unit?

    - by user29336
    I am moving into a 4 bedroom two-story unit. It’s roughly 2,200 sq ft. I want absolute max throughput possible to be achieved in all focal points. We’re all in internet related industries. Between gaming and web-development latency and throughput are major factors for us. Here’s our main focal points: 1) Garage (office). downstairs 2) Each bedroom x4. upstairs 3) Living room. downstairs The fastest line we can get is Comcast 50mbdown/5up (Wideband). I am looking for the best way to achieve wireless and wired performance for our setup. Our gaming computers may be in our bedroom, and we also may bring it down to the office every now and then for “LAN” sessions. Most wireless will be happening downstairs with our laptops, but since we may do LAN sessions then hard wired latency may be important there too. My concerns: If we do only wireless there would be too much latency for gaming. I don’t know if placing one D-link DGL 4500 on the top floor would be enough; which I currently own. (http://dlink.com/us/en/home-solutions/support/product/dgl-4500-xtreme-n-gaming-router) As far as I’m aware wireless signals transfer best top down. Would this wireless router be enough on top floor and that’s it? My second strategy was a combination of wiring and wireless but I’m not sure what’s easiest way to do this? This is a place we’re renting, so I’m not sure how much leeway we have with wiring, but we’re all pretty competent... if we can’t drill through a wall we can probably “stitch” them across the edges wherever needed. Thoughts on the optimal way to do this?

    Read the article

  • Virtual Box Networking; How to configure bridged networking on Windows 7

    - by Krist van Besien
    I have VirtualBox on Windows 7. I have two virtual machines running RHEL, that work fine when the network is set to NAT. However I want to change the network adapters for the VM's to bridged in stead of NAT. However when I go in to the VM configuration, and select bridged I also need to select an adapter, but there is nothing to select. Apparently I need to install a separate driver/filter on the network adapter. However I don't know where to start. I reinstalled VirtualBox (latest version) but did not see an option to install such driver. What should I do?

    Read the article

  • Strange behavior in networking between 64bit and 32bit

    - by Rob
    I'm having a strange behavior about my network setup. I have 2 laptops, one (Lenovo) with Windows 7 Professional 64-bit and another (Acer) with Windows 7 Ultimate 32-bit and a wireless router. I'm connecting these 2 using the router but with a strange behavior. I can ping both machines, as well as the router, but when i try to access their shared folders (\\computer_name\shared_folder) the connection starts to fail and I need to reboot both machines to get it working again. But this only happens sometimes, sometimes it works.

    Read the article

  • Will Beej's Guide to Network programming point me the right way to be able to make multiplayer games and a web broswer?

    - by Logan545
    I'm new to socket programming in C, and I've found the Beej's Guide to Networking programming. It looks fine and all, however, I just wanted to ask whether this tutorial will point me in the right direction in terms of network programming. I plan to build a game in opengl that will be multiplayer using c+ and possibly a web browser. I know this tutorial would by no means teach me how to do this, but would this be a good way to start off on my path?

    Read the article

  • Mutating Programming Language?

    - by MattiasK
    For fun I was thinking about how one could build a programming language that differs from OOP and came up with this concept. I don't have a strong foundation in computer science so it might be common place without me knowing it (more likely it's just a stupid idea :) I apologize in advance for this somewhat rambling question :) Anyways here goes: In normal OOP methods and classes are variant only upon parameters, meaning if two different classes/methods call the same method they get the same output. My, perhaps crazy idea, is that the calling method and class could be an "invisible" part of it's signature and the response could vary depending on who call's an method. Say that we have a Window object with a Break() method, now anyone (who has access) could call this method on Window with the same result. Now say that we have two different objects, Hammer and SledgeHammer. If Break need to produce different results based on these we'd pass them as parameters Break(IBluntObject bluntObject) With a mutating programming language (mpl) the operating objects on the method would be visible to the Break Method without begin explicitly defined and it could adopt itself based on them). So if SledgeHammer calls Window.Break() it would generate vastly different results than if Hammer did so. If OOP classes are black boxes then MPL are black boxes that knows who's (trying) to push it's buttons and can adapt accordingly. You could also have different permission sets on methods depending who's calling them rather than having absolute permissions like public and private. Does this have any advantage over OOP? Or perhaps I should say, would it add anything to it since you should be able to simply add this aspect to methods (just give access to a CallingMethod and CallingClass variable in context) I'm not sure, might be to hard to wrap one's head around, it would be kinda interesting to have classes that adopted themselves to who uses them though. Still it's an interesting concept, what do you think, is it viable?

    Read the article

  • How do I create my own programming language and a compiler for it

    - by Dave
    I am thorough with programming and have come across languages including BASIC, FORTRAN, COBOL, LISP, LOGO, Java, C++, C, MATLAB, Mathematica, Python, Ruby, Perl, JavaScript, Assembly and so on. I can't understand how people create programming languages and devise compilers for it. I also couldn't understand how people create OS like Windows, Mac, UNIX, DOS and so on. The other thing that is mysterious to me is how people create libraries like OpenGL, OpenCL, OpenCV, Cocoa, MFC and so on. The last thing I am unable to figure out is how scientists devise an assembly language and an assembler for a microprocessor. I would really like to learn all of these stuff and I am 15 years old. I always wanted to be a computer scientist someone like Babbage, Turing, Shannon, or Dennis Ritchie. I have already read Aho's Compiler Design and Tanenbaum's OS concepts book and they all only discuss concepts and code in a high level. They don't go into the details and nuances and how to devise a compiler or operating system. I want a concrete understanding so that I can create one myself and not just an understanding of what a thread, semaphore, process, or parsing is. I asked my brother about all this. He is a SB student in EECS at MIT and hasn't got a clue of how to actually create all these stuff in the real world. All he knows is just an understanding of Compiler Design and OS concepts like the ones that you guys have mentioned (i.e. like Thread, Synchronization, Concurrency, memory management, Lexical Analysis, Intermediate code generation and so on)

    Read the article

  • How to diagram custom programming languages, non textual?

    - by Adam
    I've used and created domain-specific languages before, plenty of times (e.g. using yacc/lex). Normally we'd start with grammar written in BNF, and a bunch of keywords. This is easy to do, easy to share. Recently, I've started working with diagrammatic programming languages - closest parallel is circuit-diagrams in electronics, where it's very difficult to express ideas in text, but very easy to express them in wiring-diagrams. This is a new and novel problem for me: how to efficiently express these mini-languages, and share concepts in them with colleagues? (i.e. how to whiteboard-program within them. Actual programming is easy - you have physical components to hand) Are there tools for this? Or good/best practices (e.g. equivalent of "always use BNF as starting point for your new DSL, and use tools like yacc to generate the parser, compiler, etc"). My googlefu is proving weak - all I get is false positives for wiring diagrams, and UML editors (since these are custom languages, UML doesn't seem to help)

    Read the article

  • How do I create my own programming language and a compiler for it

    - by Dave
    I am thorough with programming and have come across languages including BASIC, FORTRAN, COBOL, LISP, LOGO, Java, C++, C, MATLAB, Mathematica, Python, Ruby, Perl, Javascript, Assembly and so on. I can't understand how people create programming languages and devise compilers for it. I also couldn't understand how people create OS like Windows, Mac, UNIX, DOS and so on. The other thing that is mysterious to me is how people create libraries like OpenGL, OpenCL, OpenCV, Cocoa, MFC and so on. The last thing I am unable to figure out is how scientists devise an assembly language and an assembler for a microprocessor. I would really like to learn all of these stuff and I am 15 years old. I always wanted to be a computer scientist some one like Babbage, Turing, Shannon, or Dennis Ritchie. I have already read Aho's Compiler Design and Tanenbaum's OS concepts book and they all only discuss concepts and code in a high level. They don't go into the details and nuances and how to devise a compiler or operating system. I want a concrete understanding so that I can create one myself and not just an understanding of what a thread, semaphore, process, or parsing is. I asked my brother about all this. He is a SB student in EECS at MIT and hasn't got a clue of how to actually create all these stuff in the real world. All he knows is just an understanding of Compiler Design and OS concepts like the ones that you guys have mentioned (ie like Thread, Synchronisation, Concurrency, memory management, Lexical Analysis, Intermediate code generation and so on)

    Read the article

< Previous Page | 9 10 11 12 13 14 15 16 17 18 19 20  | Next Page >