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  • I want to establish a TCP/IP connection over a UART connection (Windows XP/7)

    - by michael
    I want to connect two computer via serial but for each to see each other via a TCP/IP connection. Ie, create new ethernet ports on the computers that are in actual fact serial ports. The reason for this is that I am actually testing the medium in which the serial connection is made (wireless), and part of the experiment will be to use TCP/IP. Preferably I would use something that I can configure (max packet size and setting serial delimiters).

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  • Microbenchmark showing process-switching faster than thread-switching; what's wrong?

    - by Yang
    I have two simple microbenchmarks trying to measure thread- and process-switching overheads, but the process-switching overhead. The code is living here, and r1667 is pasted below: https://assorted.svn.sourceforge.net/svnroot/assorted/sandbox/trunk/src/c/process_switch_bench.c // on zs, ~2.1-2.4us/switch #include <stdlib.h> #include <fcntl.h> #include <stdint.h> #include <stdio.h> #include <semaphore.h> #include <unistd.h> #include <sys/wait.h> #include <sys/types.h> #include <sys/time.h> #include <pthread.h> uint32_t COUNTER; pthread_mutex_t LOCK; pthread_mutex_t START; sem_t *s0, *s1, *s2; void * threads ( void * unused ) { // Wait till we may fire away sem_wait(s2); for (;;) { pthread_mutex_lock(&LOCK); pthread_mutex_unlock(&LOCK); COUNTER++; sem_post(s0); sem_wait(s1); } return 0; } int64_t timeInMS () { struct timeval t; gettimeofday(&t, NULL); return ( (int64_t)t.tv_sec * 1000 + (int64_t)t.tv_usec / 1000 ); } int main ( int argc, char ** argv ) { int64_t start; pthread_t t1; pthread_mutex_init(&LOCK, NULL); COUNTER = 0; s0 = sem_open("/s0", O_CREAT, 0022, 0); if (s0 == 0) { perror("sem_open"); exit(1); } s1 = sem_open("/s1", O_CREAT, 0022, 0); if (s1 == 0) { perror("sem_open"); exit(1); } s2 = sem_open("/s2", O_CREAT, 0022, 0); if (s2 == 0) { perror("sem_open"); exit(1); } int x, y, z; sem_getvalue(s0, &x); sem_getvalue(s1, &y); sem_getvalue(s2, &z); printf("%d %d %d\n", x, y, z); pid_t pid = fork(); if (pid) { pthread_create(&t1, NULL, threads, NULL); pthread_detach(t1); // Get start time and fire away start = timeInMS(); sem_post(s2); sem_post(s2); // Wait for about a second sleep(1); // Stop thread pthread_mutex_lock(&LOCK); // Find out how much time has really passed. sleep won't guarantee me that // I sleep exactly one second, I might sleep longer since even after being // woken up, it can take some time before I gain back CPU time. Further // some more time might have passed before I obtained the lock! int64_t time = timeInMS() - start; // Correct the number of thread switches accordingly COUNTER = (uint32_t)(((uint64_t)COUNTER * 2 * 1000) / time); printf("Number of process switches in about one second was %u\n", COUNTER); printf("roughly %f microseconds per switch\n", 1000000.0 / COUNTER); // clean up kill(pid, 9); wait(0); sem_close(s0); sem_close(s1); sem_unlink("/s0"); sem_unlink("/s1"); sem_unlink("/s2"); } else { if (1) { sem_t *t = s0; s0 = s1; s1 = t; } threads(0); // never return } return 0; } https://assorted.svn.sourceforge.net/svnroot/assorted/sandbox/trunk/src/c/thread_switch_bench.c // From <http://stackoverflow.com/questions/304752/how-to-estimate-the-thread-context-switching-overhead> // on zs, ~4-5us/switch; tried making COUNTER updated only by one thread, but no difference #include <stdlib.h> #include <stdint.h> #include <stdio.h> #include <pthread.h> #include <unistd.h> #include <sys/time.h> uint32_t COUNTER; pthread_mutex_t LOCK; pthread_mutex_t START; pthread_cond_t CONDITION; void * threads ( void * unused ) { // Wait till we may fire away pthread_mutex_lock(&START); pthread_mutex_unlock(&START); int first=1; pthread_mutex_lock(&LOCK); // If I'm not the first thread, the other thread is already waiting on // the condition, thus Ihave to wake it up first, otherwise we'll deadlock if (COUNTER > 0) { pthread_cond_signal(&CONDITION); first=0; } for (;;) { if (first) COUNTER++; pthread_cond_wait(&CONDITION, &LOCK); // Always wake up the other thread before processing. The other // thread will not be able to do anything as long as I don't go // back to sleep first. pthread_cond_signal(&CONDITION); } pthread_mutex_unlock(&LOCK); return 0; } int64_t timeInMS () { struct timeval t; gettimeofday(&t, NULL); return ( (int64_t)t.tv_sec * 1000 + (int64_t)t.tv_usec / 1000 ); } int main ( int argc, char ** argv ) { int64_t start; pthread_t t1; pthread_t t2; pthread_mutex_init(&LOCK, NULL); pthread_mutex_init(&START, NULL); pthread_cond_init(&CONDITION, NULL); pthread_mutex_lock(&START); COUNTER = 0; pthread_create(&t1, NULL, threads, NULL); pthread_create(&t2, NULL, threads, NULL); pthread_detach(t1); pthread_detach(t2); // Get start time and fire away start = timeInMS(); pthread_mutex_unlock(&START); // Wait for about a second sleep(1); // Stop both threads pthread_mutex_lock(&LOCK); // Find out how much time has really passed. sleep won't guarantee me that // I sleep exactly one second, I might sleep longer since even after being // woken up, it can take some time before I gain back CPU time. Further // some more time might have passed before I obtained the lock! int64_t time = timeInMS() - start; // Correct the number of thread switches accordingly COUNTER = (uint32_t)(((uint64_t)COUNTER * 2 * 1000) / time); printf("Number of thread switches in about one second was %u\n", COUNTER); printf("roughly %f microseconds per switch\n", 1000000.0 / COUNTER); return 0; }

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  • Bridge or Factory and How

    - by Chris
    I'm trying to learn patterns and I've got a job that is screaming for a pattern, I just know it but I can't figure it out. I know the filter type is something that can be abstracted and possibly bridged. I'M NOT LOOKING FOR A CODE REWRITE JUST SUGGESTIONS. I'm not looking for someone to do my job. I would like to know how patterns could be applied to this example. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; using System.IO; using System.Xml; using System.Text.RegularExpressions; namespace CopyTool { class CopyJob { public enum FilterType { TextFilter, RegExFilter, NoFilter } public FilterType JobFilterType { get; set; } private string _jobName; public string JobName { get { return _jobName; } set { _jobName = value; } } private int currentIndex; public int CurrentIndex { get { return currentIndex; } } private DataSet ds; public int MaxJobs { get { return ds.Tables["Job"].Rows.Count; } } private string _filter; public string Filter { get { return _filter; } set { _filter = value; } } private string _fromFolder; public string FromFolder { get { return _fromFolder; } set { if (Directory.Exists(value)) { _fromFolder = value; } else { throw new DirectoryNotFoundException(String.Format("Folder not found: {0}", value)); } } } private List<string> _toFolders; public List<string> ToFolders { get { return _toFolders; } } public CopyJob() { Initialize(); } private void Initialize() { if (ds == null) { ds = new DataSet(); } ds.ReadXml(Properties.Settings.Default.ConfigLocation); LoadValues(0); } public void Execute() { ExecuteJob(FromFolder, _toFolders, Filter, JobFilterType); } public void ExecuteAll() { string OrigPath; List<string> DestPaths; string FilterText; FilterType FilterWay; foreach (DataRow rw in ds.Tables["Job"].Rows) { OrigPath = rw["FromFolder"].ToString(); FilterText = rw["FilterText"].ToString(); switch (rw["FilterType"].ToString()) { case "TextFilter": FilterWay = FilterType.TextFilter; break; case "RegExFilter": FilterWay = FilterType.RegExFilter; break; default: FilterWay = FilterType.NoFilter; break; } DestPaths = new List<string>(); foreach (DataRow crw in rw.GetChildRows("Job_ToFolder")) { DestPaths.Add(crw["FolderPath"].ToString()); } ExecuteJob(OrigPath, DestPaths, FilterText, FilterWay); } } private void ExecuteJob(string OrigPath, List<string> DestPaths, string FilterText, FilterType FilterWay) { FileInfo[] files; switch (FilterWay) { case FilterType.RegExFilter: files = GetFilesByRegEx(new Regex(FilterText), OrigPath); break; case FilterType.TextFilter: files = GetFilesByFilter(FilterText, OrigPath); break; default: files = new DirectoryInfo(OrigPath).GetFiles(); break; } foreach (string fld in DestPaths) { CopyFiles(files, fld); } } public void MoveToJob(int RecordNumber) { Save(); LoadValues(RecordNumber - 1); } public void AddToFolder(string folderPath) { if (Directory.Exists(folderPath)) { _toFolders.Add(folderPath); } else { throw new DirectoryNotFoundException(String.Format("Folder not found: {0}", folderPath)); } } public void DeleteToFolder(int index) { _toFolders.RemoveAt(index); } public void Save() { DataRow rw = ds.Tables["Job"].Rows[currentIndex]; rw["JobName"] = _jobName; rw["FromFolder"] = _fromFolder; rw["FilterText"] = _filter; switch (JobFilterType) { case FilterType.RegExFilter: rw["FilterType"] = "RegExFilter"; break; case FilterType.TextFilter: rw["FilterType"] = "TextFilter"; break; default: rw["FilterType"] = "NoFilter"; break; } DataRow[] ToFolderRows = ds.Tables["Job"].Rows[currentIndex].GetChildRows("Job_ToFolder"); for (int i = 0; i <= ToFolderRows.GetUpperBound(0); i++) { ToFolderRows[i].Delete(); } foreach (string fld in _toFolders) { DataRow ToFolderRow = ds.Tables["ToFolder"].NewRow(); ToFolderRow["JobId"] = ds.Tables["Job"].Rows[currentIndex]["JobId"]; ToFolderRow["Job_Id"] = ds.Tables["Job"].Rows[currentIndex]["Job_Id"]; ToFolderRow["FolderPath"] = fld; ds.Tables["ToFolder"].Rows.Add(ToFolderRow); } } public void Delete() { ds.Tables["Job"].Rows.RemoveAt(currentIndex); LoadValues(currentIndex++); } public void MoveNext() { Save(); currentIndex++; LoadValues(currentIndex); } public void MovePrevious() { Save(); currentIndex--; LoadValues(currentIndex); } public void MoveFirst() { Save(); LoadValues(0); } public void MoveLast() { Save(); LoadValues(ds.Tables["Job"].Rows.Count - 1); } public void CreateNew() { Save(); int MaxJobId = 0; Int32.TryParse(ds.Tables["Job"].Compute("Max(JobId)", "").ToString(), out MaxJobId); DataRow rw = ds.Tables["Job"].NewRow(); rw["JobId"] = MaxJobId + 1; ds.Tables["Job"].Rows.Add(rw); LoadValues(ds.Tables["Job"].Rows.IndexOf(rw)); } public void Commit() { Save(); ds.WriteXml(Properties.Settings.Default.ConfigLocation); } private void LoadValues(int index) { if (index > ds.Tables["Job"].Rows.Count - 1) { currentIndex = ds.Tables["Job"].Rows.Count - 1; } else if (index < 0) { currentIndex = 0; } else { currentIndex = index; } DataRow rw = ds.Tables["Job"].Rows[currentIndex]; _jobName = rw["JobName"].ToString(); _fromFolder = rw["FromFolder"].ToString(); _filter = rw["FilterText"].ToString(); switch (rw["FilterType"].ToString()) { case "TextFilter": JobFilterType = FilterType.TextFilter; break; case "RegExFilter": JobFilterType = FilterType.RegExFilter; break; default: JobFilterType = FilterType.NoFilter; break; } if (_toFolders == null) _toFolders = new List<string>(); _toFolders.Clear(); foreach (DataRow crw in rw.GetChildRows("Job_ToFolder")) { AddToFolder(crw["FolderPath"].ToString()); } } private static FileInfo[] GetFilesByRegEx(Regex rgx, string locPath) { DirectoryInfo d = new DirectoryInfo(locPath); FileInfo[] fullFileList = d.GetFiles(); List<FileInfo> filteredList = new List<FileInfo>(); foreach (FileInfo fi in fullFileList) { if (rgx.IsMatch(fi.Name)) { filteredList.Add(fi); } } return filteredList.ToArray(); } private static FileInfo[] GetFilesByFilter(string filter, string locPath) { DirectoryInfo d = new DirectoryInfo(locPath); FileInfo[] fi = d.GetFiles(filter); return fi; } private void CopyFiles(FileInfo[] files, string destPath) { foreach (FileInfo fi in files) { bool success = false; int i = 0; string copyToName = fi.Name; string copyToExt = fi.Extension; string copyToNameWithoutExt = Path.GetFileNameWithoutExtension(fi.FullName); while (!success && i < 100) { i++; try { if (File.Exists(Path.Combine(destPath, copyToName))) throw new CopyFileExistsException(); File.Copy(fi.FullName, Path.Combine(destPath, copyToName)); success = true; } catch (CopyFileExistsException ex) { copyToName = String.Format("{0} ({1}){2}", copyToNameWithoutExt, i, copyToExt); } } } } } public class CopyFileExistsException : Exception { public string Message; } }

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  • Synchronizing time between two Windows 7 machines connected with a LAN cable

    - by Markus Roth
    I have a number laptops that run our application while connected to each other in pairs with an ethernet cable, but not connected to any external network or the internet. T I need the connected pair to synchronize their system times, but since every computer needs to be able to synch with any other computer, I can't define one computer to be a time-server and the other to be a client. Is there a way to do this with NTP? Or some other way?

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  • How to assemble a WAV file?

    - by David
    I'm doing an educational project in which 1) I record voice commands on a separate device and after appropriate processing etc... 2) I send 16-bit samples encapsulated in UDP packets over Ethernet to the PC. After receiving the packets and "extracting" data (samples) from them, I need to assemble the samples to a WAV file. Any example code? Any suggestions?

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  • What does this pointer-heavy C code do?

    - by justRadojko
    Could someone explain to me what should two following lines do: s.httpheaderline[s.httpheaderlineptr] = *(char *)uip_appdata; ++((char *)uip_appdata); This is taken from uIP code for microcontrollers. s - structure httpheaderline - http packet presented as a string httpheadrlineptr - integer value uip_appdata - received ethernet packet (string) If some more info is needed please let me know. BTW. Eclipse is reporting an error on the second line with message Invalid lvalue in increment so i'm trying to figure out how to solve this.

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  • How to assemble a WAV file, C# preferred?!

    - by David
    Hi guys! I'm doing an educational project in which 1) I record voice commands on a separate device and after appropriate processing etc... 2) I send 16-bit samples encapsulated in UDP packets over Ethernet to the PC. After receiving the packets and "extracting" data (samples) from them, I need to assemble the samples to a WAV file. Any example code? Any suggestions? Thank you in advance!

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  • I wanna make a UDP comunication between two or more computers using c++ on linux

    - by HMojtaba
    Hi every one! I really need to make this connection throw wireless (or lan ethernet). I have done this on windows (VS2008 C#, sockets), but here on linux (ubuntu 10.04) I have installed mono, and i can handle many things there, but it's speed is unacceptable for my 600MHz processor. so i decided to move on c++, but i'm new to c++ and i'm not familiar to many of it's headers. Is there any header or any library which can do that for me? thanks

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  • How to bridge Debian guest VM to VPN via Cisco AnyConnect Client running on Windows Vista host

    - by bgoodr
    I am running Cisco Anyconnect VPN Client version 2.5.3054 on a laptop running Windows Vista Home Premium (version 6.0.6002) Service Pack 2. I am running the VMware Player version 4.0.2 build-591240. The host operating system running under VMware Player is Debian 6.0.2.1 i386. The laptop is connected to a wireless connection, and I can browse the web from Windows Vista using Firefox just fine. I am able to boot into the Debian VM and open up a browser and access websites on the WAN from within the VM just fine. I can ping real Linux hosts on my LAN via: ping <lan_system>.local where <lan_system> is the hostname returned from uname -a on that system on my LAN. From a DOS CMD shell, I am able to ping hosts that exist on the remote network served by the Cisco AnyConnect Client's VPN network (and without the .local suffix applied as above): ping <remote_system> However, from within the Debian VM, I expect to be able to also ping those same remote hosts (<remote_system>) that are tunnelled over the VPN set up by Cisco AnyConnect Client. Let's say that I can ping a <remote_system> called flubber from a DOS CMD prompt just fine. When I execute Linux ping command from inside the Debian VM via: ping flubber It returns immediately with this output: ping: unknown host flubber For reference since I suspect it will be useful, here is the output of the route print command from the DOS CMD prompt: route print =========================================================================== Interface List 30 ...00 05 9a 3c 7a 00 ...... Cisco AnyConnect VPN Virtual Miniport Adapter for Windows 11 ...00 1b 9e c4 de e5 ...... Atheros AR5007EG Wireless Network Adapter 26 ...00 50 56 c0 00 01 ...... VMware Virtual Ethernet Adapter for VMnet1 28 ...00 50 56 c0 00 08 ...... VMware Virtual Ethernet Adapter for VMnet8 1 ........................... Software Loopback Interface 1 12 ...02 00 54 55 4e 01 ...... Teredo Tunneling Pseudo-Interface 13 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3 32 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #4 27 ...00 00 00 00 00 00 00 e0 isatap.{E5292CF6-4FBB-4320-806D-A6B366769255} 17 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2 20 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #8 22 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #10 24 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #11 25 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #12 29 ...00 00 00 00 00 00 00 e0 isatap.{C3852986-5053-4E2E-BE60-52EA2FCF5899} 41 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #14 =========================================================================== At the top window border of the VM, clicking on Virtual Machine, then clicking on Virtual Machine Settings, then clicking on Network Adapter, I have these two options checked: [X] Bridged: Connected directly to the physical Network [X] Replicate physical network connection state [ ] NAT: used to share the hosts's IP address [ ] Host-only: A private network shared with the host [ ] LAN segment: [ ] <LAN Segments...> <Advanced> I've toyed with the other options such as NAT and Host-only but that had no effect. Is there some way to allow the VM to access those <remote_system>'s?

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  • What does it mean when ARP shows <incomplete> on eth1

    - by Geoff Dalgas
    We have been using HAProxy along with heartbeat from the Linux-HA project. We are using two linux instances to provide a failover. Each server has with their own public IP and a single IP which is shared between the two using a virtual interface (eth1:1) at IP: 69.59.196.211 The virtual interface (eth1:1) IP 69.59.196.211 is configured as the gateway for the windows servers behind them and we use ip_forwarding to route traffic. We are experiencing an occasional network outage on one of our windows servers behind our linux gateways. HAProxy will detect the server is offline which we can verify by remoting to the failed server and attempting to ping the gateway: Pinging 69.59.196.211 with 32 bytes of data: Reply from 69.59.196.220: Destination host unreachable. Running arp -a on this failed server shows that there is no entry for the gateway address (69.59.196.211): Interface: 69.59.196.220 --- 0xa Internet Address Physical Address Type 69.59.196.161 00-26-88-63-c7-80 dynamic 69.59.196.210 00-15-5d-0a-3e-0e dynamic 69.59.196.212 00-21-5e-4d-45-c9 dynamic 69.59.196.213 00-15-5d-00-b2-0d dynamic 69.59.196.215 00-21-5e-4d-61-1a dynamic 69.59.196.217 00-21-5e-4d-2c-e8 dynamic 69.59.196.219 00-21-5e-4d-38-e5 dynamic 69.59.196.221 00-15-5d-00-b2-0d dynamic 69.59.196.222 00-15-5d-0a-3e-09 dynamic 69.59.196.223 ff-ff-ff-ff-ff-ff static 224.0.0.22 01-00-5e-00-00-16 static 224.0.0.252 01-00-5e-00-00-fc static 225.0.0.1 01-00-5e-00-00-01 static On our linux gateway instances arp -a shows: peak-colo-196-220.peak.org (69.59.196.220) at <incomplete> on eth1 stackoverflow.com (69.59.196.212) at 00:21:5e:4d:45:c9 [ether] on eth1 peak-colo-196-215.peak.org (69.59.196.215) at 00:21:5e:4d:61:1a [ether] on eth1 peak-colo-196-219.peak.org (69.59.196.219) at 00:21:5e:4d:38:e5 [ether] on eth1 peak-colo-196-222.peak.org (69.59.196.222) at 00:15:5d:0a:3e:09 [ether] on eth1 peak-colo-196-209.peak.org (69.59.196.209) at 00:26:88:63:c7:80 [ether] on eth1 peak-colo-196-217.peak.org (69.59.196.217) at 00:21:5e:4d:2c:e8 [ether] on eth1 Why would arp occasionally set the entry for this failed server as <incomplete>? Should we be defining our arp entries statically? I've always left arp alone since it works 99% of the time, but in this one instance it appears to be failing. Are there any additional troubleshooting steps we can take help resolve this issue? THINGS WE HAVE TRIED I added a static arp entry for testing on one of the linux gateways which still didn't help. root@haproxy2:~# arp -a peak-colo-196-215.peak.org (69.59.196.215) at 00:21:5e:4d:61:1a [ether] on eth1 peak-colo-196-221.peak.org (69.59.196.221) at 00:15:5d:00:b2:0d [ether] on eth1 stackoverflow.com (69.59.196.212) at 00:21:5e:4d:45:c9 [ether] on eth1 peak-colo-196-219.peak.org (69.59.196.219) at 00:21:5e:4d:38:e5 [ether] on eth1 peak-colo-196-209.peak.org (69.59.196.209) at 00:26:88:63:c7:80 [ether] on eth1 peak-colo-196-217.peak.org (69.59.196.217) at 00:21:5e:4d:2c:e8 [ether] on eth1 peak-colo-196-220.peak.org (69.59.196.220) at 00:21:5e:4d:30:8d [ether] PERM on eth1 root@haproxy2:~# arp -i eth1 -s 69.59.196.220 00:21:5e:4d:30:8d root@haproxy2:~# ping 69.59.196.220 PING 69.59.196.220 (69.59.196.220) 56(84) bytes of data. --- 69.59.196.220 ping statistics --- 7 packets transmitted, 0 received, 100% packet loss, time 6006ms Rebooting the windows web server solves this issue temporarily with no other changes to the network but our experience shows this issue will come back. Swapping network cards and switches I noticed the link light on the port of the switch for the failed windows server was running at 100Mb instead of 1Gb on the failed interface. I moved the cable to several other open ports and the link indicated 100Mb for each port that I tried. I also swapped the cable with the same result. I tried changing the properties of the network card in windows and the server locked up and required a hard reset after clicking apply. This windows server has two physical network interfaces so I have swapped the cables and network settings on the two interfaces to see if the problem follows the interface. If the public interface goes down again we will know that it is not an issue with the network card. (We also tried another switch we have on hand, no change) Changing network hardware driver versions We've had the same problem with the latest Broadcom driver, as well as the built-in driver that ships in Windows Server 2008 R2. Replacing network cables As a last ditch effort we remembered another change that occurred was the replacement of all of the patch cords between our servers / switch. We had purchased two sets, one green of lengths 1ft - 3ft for the private interfaces and another set of red cables for the public interfaces. We swapped out all of the public interface patch cables with a different brand and ran our servers without issue for a full week ... aaaaaand then the problem recurred. Disable checksum offload, remove TProxy We also tried disabling TCP/IP checksum offload in the driver, no change. We're now pulling out TProxy and moving to a more traditional x-forwarded-for network arrangement without any fancy IP address rewriting. We'll see if that helps.

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  • eth0 and eth1 both assigned same IP on boot

    - by Banjer
    I have a physical SLES 11 SP2 server on a Sun Fire x4140 that is giving me problems with networking upon reboot. The NICs are onboard. The networking appears successful during boot, but network services such as nfs fail hard. This is because eth0 and eth1 are both receiving the same configuration and are both ifup-ed. Once everything times out and I'm at the console, ifconfig shows that eth0 and eth1 are UP and running with the same IP. Attempting to ping anything in that subnet fails. Restarting the network service fixes the issue. eth0 is the correct NIC that should be configured as primary, per the MAC address. Question: Whats causing eth1 to be brought up with the same config as eth0?? I do not have a config script set up for eth1: banjer@harp:~> ls -la /etc/sysconfig/network/ total 104 drwxr-xr-x 6 root root 4096 Jun 11 12:21 . drwxr-xr-x 6 root root 4096 Apr 10 09:46 .. -rw-r--r-- 1 root root 13916 Apr 10 09:32 config -rw-r--r-- 1 root root 9952 Apr 10 09:36 dhcp -rw------- 1 root root 180 Jun 11 12:21 ifcfg-eth0 -rw------- 1 root root 180 Jun 11 12:21 ifcfg-eth3 -rw------- 1 root root 172 Feb 1 08:32 ifcfg-lo -rw-r--r-- 1 root root 29333 Feb 1 08:32 ifcfg.template drwxr-xr-x 2 root root 4096 Apr 10 09:32 if-down.d -rw-r--r-- 1 root root 239 Feb 1 08:32 ifroute-lo drwxr-xr-x 2 root root 4096 Apr 10 09:33 if-up.d drwx------ 2 root root 4096 May 5 2010 providers -rw-r--r-- 1 root root 25 Nov 16 2010 routes drwxr-xr-x 2 root root 4096 Apr 10 09:36 scripts On a side note, eth3 is also configured with an IP in a different subnet, but this has not posed any problems. FYI the kernel module being used is forcedeth. banjer@harp:~> sudo cat /etc/sysconfig/network/ifcfg-eth0 BOOTPROTO='static' BROADCAST='' ETHTOOL_OPTIONS='' IPADDR='172.21.64.25/20' MTU='' NAME='MCP55 Ethernet' NETWORK='' REMOTE_IPADDR='' STARTMODE='auto' USERCONTROL='no' ONBOOT="yes" Here's eth3 in case you need to see it: banjer@harp:~> sudo cat /etc/sysconfig/network/ifcfg-eth3 BOOTPROTO='static' BROADCAST='' ETHTOOL_OPTIONS='' IPADDR='172.11.200.4/24' MTU='' NAME='MCP55 Ethernet' NETWORK='' REMOTE_IPADDR='' STARTMODE='auto' USERCONTROL='no' ONBOOT="yes" Perhaps is something related to udev? 70-persistent-net-rules looks OK to me, but I may not understand it completely. banjer@harp:~> cat /etc/udev/rules.d/70-persistent-net.rules # This file was automatically generated by the /lib/udev/write_net_rules # program, run by the persistent-net-generator.rules rules file. # # You can modify it, as long as you keep each rule on a single # line, and change only the value of the NAME= key. # PCI device 0x10de:0x0373 (forcedeth) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:18:4f:8d:85:4c", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2" # PCI device 0x10de:0x0373 (forcedeth) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:18:4f:8d:85:4a", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0" # PCI device 0x10de:0x0373 (forcedeth) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:18:4f:8d:85:4b", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1" # PCI device 0x10de:0x0373 (forcedeth) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:18:4f:8d:85:4d", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth3" # PCI device 0x1077:0x3032 (qla3xxx) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:c1:dd:0e:34:6c", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth4" Any other thoughts on what would cause this?

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  • Diagnosing packet loss / high latency in Ubuntu

    - by Sam Gammon
    We have a Linux box (Ubuntu 12.04) running Nginx (1.5.2), which acts as a reverse proxy/load balancer to some Tornado and Apache hosts. The upstream servers are physically and logically close (same DC, sometimes same-rack) and show sub-millisecond latency between them: PING appserver (10.xx.xx.112) 56(84) bytes of data. 64 bytes from appserver (10.xx.xx.112): icmp_req=1 ttl=64 time=0.180 ms 64 bytes from appserver (10.xx.xx.112): icmp_req=2 ttl=64 time=0.165 ms 64 bytes from appserver (10.xx.xx.112): icmp_req=3 ttl=64 time=0.153 ms We receive a sustained load of about 500 requests per second, and are currently seeing regular packet loss / latency spikes from the Internet, even from basic pings: sam@AM-KEEN ~> ping -c 1000 loadbalancer PING 50.xx.xx.16 (50.xx.xx.16): 56 data bytes 64 bytes from loadbalancer: icmp_seq=0 ttl=56 time=11.624 ms 64 bytes from loadbalancer: icmp_seq=1 ttl=56 time=10.494 ms ... many packets later ... Request timeout for icmp_seq 2 64 bytes from loadbalancer: icmp_seq=2 ttl=56 time=1536.516 ms 64 bytes from loadbalancer: icmp_seq=3 ttl=56 time=536.907 ms 64 bytes from loadbalancer: icmp_seq=4 ttl=56 time=9.389 ms ... many packets later ... Request timeout for icmp_seq 919 64 bytes from loadbalancer: icmp_seq=918 ttl=56 time=2932.571 ms 64 bytes from loadbalancer: icmp_seq=919 ttl=56 time=1932.174 ms 64 bytes from loadbalancer: icmp_seq=920 ttl=56 time=932.018 ms 64 bytes from loadbalancer: icmp_seq=921 ttl=56 time=6.157 ms --- 50.xx.xx.16 ping statistics --- 1000 packets transmitted, 997 packets received, 0.3% packet loss round-trip min/avg/max/stddev = 5.119/52.712/2932.571/224.629 ms The pattern is always the same: things operate fine for a while (<20ms), then a ping drops completely, then three or four high-latency pings (1000ms), then it settles down again. Traffic comes in through a bonded public interface (we will call it bond0) configured as such: bond0 Link encap:Ethernet HWaddr 00:xx:xx:xx:xx:5d inet addr:50.xx.xx.16 Bcast:50.xx.xx.31 Mask:255.255.255.224 inet6 addr: <ipv6 address> Scope:Global inet6 addr: <ipv6 address> Scope:Link UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 RX packets:527181270 errors:1 dropped:4 overruns:0 frame:1 TX packets:413335045 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:240016223540 (240.0 GB) TX bytes:104301759647 (104.3 GB) Requests are then submitted via HTTP to upstream servers on the private network (we can call it bond1), which is configured like so: bond1 Link encap:Ethernet HWaddr 00:xx:xx:xx:xx:5c inet addr:10.xx.xx.70 Bcast:10.xx.xx.127 Mask:255.255.255.192 inet6 addr: <ipv6 address> Scope:Link UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 RX packets:430293342 errors:1 dropped:2 overruns:0 frame:1 TX packets:466983986 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:77714410892 (77.7 GB) TX bytes:227349392334 (227.3 GB) Output of uname -a: Linux <hostname> 3.5.0-42-generic #65~precise1-Ubuntu SMP Wed Oct 2 20:57:18 UTC 2013 x86_64 GNU/Linux We have customized sysctl.conf in an attempt to fix the problem, with no success. Output of /etc/sysctl.conf (with irrelevant configs omitted): # net: core net.core.netdev_max_backlog = 10000 # net: ipv4 stack net.ipv4.tcp_ecn = 2 net.ipv4.tcp_sack = 1 net.ipv4.tcp_fack = 1 net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_tw_recycle = 0 net.ipv4.tcp_timestamps = 1 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_no_metrics_save = 1 net.ipv4.tcp_max_syn_backlog = 10000 net.ipv4.tcp_congestion_control = cubic net.ipv4.ip_local_port_range = 8000 65535 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_synack_retries = 2 net.ipv4.tcp_thin_dupack = 1 net.ipv4.tcp_thin_linear_timeouts = 1 net.netfilter.nf_conntrack_max = 99999999 net.netfilter.nf_conntrack_tcp_timeout_established = 300 Output of dmesg -d, with non-ICMP UFW messages suppressed: [508315.349295 < 19.852453>] [UFW BLOCK] IN=bond1 OUT= MAC=<mac addresses> SRC=118.xx.xx.143 DST=50.xx.xx.16 LEN=68 TOS=0x00 PREC=0x00 TTL=51 ID=43221 PROTO=ICMP TYPE=3 CODE=1 [SRC=50.xx.xx.16 DST=118.xx.xx.143 LEN=40 TOS=0x00 PREC=0x00 TTL=249 ID=10220 DF PROTO=TCP SPT=80 DPT=53817 WINDOW=8190 RES=0x00 ACK FIN URGP=0 ] [517787.732242 < 0.443127>] Peer 190.xx.xx.131:59705/80 unexpectedly shrunk window 1155488866:1155489425 (repaired) How can I go about diagnosing the cause of this problem, on a Debian-family Linux box?

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  • Dhcpd Daemon is trying to lease itself?

    - by tommieb75
    I have a Slackware Linux 13.0 box with two interfaces, eth0 and eth1. I have set this box up to be on the 192.168.1.0/24 network, with subnet mask of 255.255.255.0. I am trying to run a dhcpd server on this box to service two interfaces above, so I subnetted the 192.168.1.0/24 network into two subnets. For eth0 192.168.1.1, subnet mask 255.255.255.128, broadcast mask 192.168.1.127. For eth1 192.168.1.129, subnet mask 255.255.255.128, broadcast mask 192.168.1.255. Both the interfaces are assigned manually. eth0 Link encap:Ethernet HWaddr 00:00:00:00:00:00 inet addr:192.168.1.1 Bcast:192.168.1.127 Mask:255.255.255.128 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:39 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:1404 (1.3 KiB) Interrupt:11 Base address:0x8000 Memory:faffc000-faffcfff eth1 Link encap:Ethernet HWaddr 00:00:00:00:00:00 inet addr:192.168.1.128 Bcast:192.168.1.255 Mask:255.255.255.128 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:10003 errors:0 dropped:0 overruns:0 frame:0 TX packets:13286 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1589229 (1.5 MiB) TX bytes:9900005 (9.4 MiB) Interrupt:11 Here is the dhcpd.conf set up authoritative; ddns-update-style interim; ignore client-updates; subnet 192.168.1.0 netmask 255.255.255.128 { range 192.168.1.2 192.168.1.126; default-lease-time 86400; max-lease-time 86400; option routers 192.168.1.1; option ip-forwarding off; option domain-name-servers 208.67.222.222, 208.67.220.220; option broadcast-address 192.168.1.127; option subnet-mask 255.255.255.128; } subnet 192.168.1.128 netmask 255.255.255.128 { range 192.168.1.129 192.168.1.254; default-lease-time 86400; max-lease-time 86400; option routers 192.168.1.1; option ip-forwarding off; option domain-name-servers 208.67.222.222, 208.67.220.220; option broadcast-address 192.168.1.255; option subnet-mask 255.255.255.128; } This is what is showing in the log Apr 10 18:09:58 inspiron8600 dhcpd: DHCPDISCOVER from 00:00:00:00:00:00 (inspiron8600) via eth1 Apr 10 18:09:58 inspiron8600 dhcpd: DHCPOFFER on 192.168.1.131 to 00:00:00:00:00:00 (inspiron8600) via eth1 Apr 10 18:10:01 inspiron8600 dhcpcd[3832]: eth1: adding IP address 169.254.153.6/16 This is happening spuriously, and the log gets filled up with nonsense..so my question is this: How do I stop this from happening? And why would it be trying to give itself a lease? I am sure I have missed something but cannot see it and would appreciate a pair of eyes from the community to spot the obvious flaw!

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  • NIC Bonding/balance-rr with Dell PowerConnect 5324

    - by Branden Martin
    I'm trying to get NIC bonding to work with balance-rr so that three NIC ports are combined, so that instead of getting 1 Gbps we get 3 Gbps. We are doing this on two servers connected to the same switch. However, we're only getting the speed of one physical link. We are using 1 Dell PowerConnect 5324, SW version 2.0.1.3, Boot version 1.0.2.02, HW version 00.00.02. Both servers are CentOS 5.9 (Final) running OnApp Hypervisor (CloudBoot) Server 1 is using ports g5-g7 in port-channel 1. Server 2 is using ports g9-g11 in port-channel 2. Switch show interface status Port Type Duplex Speed Neg ctrl State Pressure Mode -------- ------------ ------ ----- -------- ---- ----------- -------- ------- g1 1G-Copper -- -- -- -- Down -- -- g2 1G-Copper Full 1000 Enabled Off Up Disabled Off g3 1G-Copper -- -- -- -- Down -- -- g4 1G-Copper -- -- -- -- Down -- -- g5 1G-Copper Full 1000 Enabled Off Up Disabled Off g6 1G-Copper Full 1000 Enabled Off Up Disabled Off g7 1G-Copper Full 1000 Enabled Off Up Disabled On g8 1G-Copper Full 1000 Enabled Off Up Disabled Off g9 1G-Copper Full 1000 Enabled Off Up Disabled On g10 1G-Copper Full 1000 Enabled Off Up Disabled On g11 1G-Copper Full 1000 Enabled Off Up Disabled Off g12 1G-Copper Full 1000 Enabled Off Up Disabled On g13 1G-Copper -- -- -- -- Down -- -- g14 1G-Copper -- -- -- -- Down -- -- g15 1G-Copper -- -- -- -- Down -- -- g16 1G-Copper -- -- -- -- Down -- -- g17 1G-Copper -- -- -- -- Down -- -- g18 1G-Copper -- -- -- -- Down -- -- g19 1G-Copper -- -- -- -- Down -- -- g20 1G-Copper -- -- -- -- Down -- -- g21 1G-Combo-C -- -- -- -- Down -- -- g22 1G-Combo-C -- -- -- -- Down -- -- g23 1G-Combo-C -- -- -- -- Down -- -- g24 1G-Combo-C Full 100 Enabled Off Up Disabled On Flow Link Ch Type Duplex Speed Neg control State -------- ------- ------ ----- -------- ------- ----------- ch1 1G Full 1000 Enabled Off Up ch2 1G Full 1000 Enabled Off Up ch3 -- -- -- -- -- Not Present ch4 -- -- -- -- -- Not Present ch5 -- -- -- -- -- Not Present ch6 -- -- -- -- -- Not Present ch7 -- -- -- -- -- Not Present ch8 -- -- -- -- -- Not Present Server 1: cat /etc/sysconfig/network-scripts/ifcfg-eth3 DEVICE=eth3 HWADDR=00:1b:21:ac:d5:55 USERCTL=no BOOTPROTO=none ONBOOT=yes MASTER=onappstorebond SLAVE=yes cat /etc/sysconfig/network-scripts/ifcfg-eth4 DEVICE=eth4 HWADDR=68:05:ca:18:28:ae USERCTL=no BOOTPROTO=none ONBOOT=yes MASTER=onappstorebond SLAVE=yes cat /etc/sysconfig/network-scripts/ifcfg-eth5 DEVICE=eth5 HWADDR=68:05:ca:18:28:af USERCTL=no BOOTPROTO=none ONBOOT=yes MASTER=onappstorebond SLAVE=yes cat /etc/sysconfig/network-scripts/ifcfg-onappstorebond DEVICE=onappstorebond IPADDR=10.200.52.1 NETMASK=255.255.0.0 GATEWAY=10.200.2.254 NETWORK=10.200.0.0 USERCTL=no BOOTPROTO=none ONBOOT=yes cat /proc/net/bonding/onappstorebond Ethernet Channel Bonding Driver: v3.4.0-1 (October 7, 2008) Bonding Mode: load balancing (round-robin) MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 0 Down Delay (ms): 0 Slave Interface: eth3 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 0 Permanent HW addr: 00:1b:21:ac:d5:55 Slave Interface: eth4 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 0 Permanent HW addr: 68:05:ca:18:28:ae Slave Interface: eth5 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 0 Permanent HW addr: 68:05:ca:18:28:af Server 2: cat /etc/sysconfig/network-scripts/ifcfg-eth3 DEVICE=eth3 HWADDR=00:1b:21:ac:d5:a7 USERCTL=no BOOTPROTO=none ONBOOT=yes MASTER=onappstorebond SLAVE=yes cat /etc/sysconfig/network-scripts/ifcfg-eth4 DEVICE=eth4 HWADDR=68:05:ca:18:30:30 USERCTL=no BOOTPROTO=none ONBOOT=yes MASTER=onappstorebond SLAVE=yes cat /etc/sysconfig/network-scripts/ifcfg-eth5 DEVICE=eth5 HWADDR=68:05:ca:18:30:31 USERCTL=no BOOTPROTO=none ONBOOT=yes MASTER=onappstorebond SLAVE=yes cat /etc/sysconfig/network-scripts/ifcfg-onappstorebond DEVICE=onappstorebond IPADDR=10.200.53.1 NETMASK=255.255.0.0 GATEWAY=10.200.3.254 NETWORK=10.200.0.0 USERCTL=no BOOTPROTO=none ONBOOT=yes cat /proc/net/bonding/onappstorebond Ethernet Channel Bonding Driver: v3.4.0-1 (October 7, 2008) Bonding Mode: load balancing (round-robin) MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 0 Down Delay (ms): 0 Slave Interface: eth3 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 0 Permanent HW addr: 00:1b:21:ac:d5:a7 Slave Interface: eth4 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 0 Permanent HW addr: 68:05:ca:18:30:30 Slave Interface: eth5 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 0 Permanent HW addr: 68:05:ca:18:30:31 Here are the results of iperf. ------------------------------------------------------------ Client connecting to 10.200.52.1, TCP port 5001 TCP window size: 27.7 KByte (default) ------------------------------------------------------------ [ 3] local 10.200.3.254 port 53766 connected with 10.200.52.1 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 950 MBytes 794 Mbits/sec

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  • Vagrant (Virtualbox) host-only multiple node networking issue

    - by Lorin Hochstein
    I'm trying to use a multi-VM vagrant environment as a testbed for deploying OpenStack, and I've run into a networking problem with trying to communicate from one VM, to a VM-inside-of-a-VM. I have two Vagrant nodes, a cloud controller node and a compute node. I'm using host-only networking. My Vagrantfile looks like this: Vagrant::Config.run do |config| config.vm.box = "precise64" config.vm.define :controller do |controller_config| controller_config.vm.network :hostonly, "192.168.206.130" # eth1 controller_config.vm.network :hostonly, "192.168.100.130" # eth2 controller_config.vm.host_name = "controller" end config.vm.define :compute1 do |compute1_config| compute1_config.vm.network :hostonly, "192.168.206.131" # eth1 compute1_config.vm.network :hostonly, "192.168.100.131" # eth2 compute1_config.vm.host_name = "compute1" compute1_config.vm.customize ["modifyvm", :id, "--memory", 1024] end end When I try to start up a (QEMU-based) VM, it boots successfully on compute1, and its virtual nic (vnet0) is connected via a bridge, br100: root@compute1:~# brctl show 100 bridge name bridge id STP enabled interfaces br100 8000.08002798c6ef no eth2 vnet0 When the QEMU VM makes a request to the DHCP server (dnsmasq) running on controller, I can see the request reaches the controller because of the output on the syslog on the controller: Aug 6 02:34:56 precise64 dnsmasq-dhcp[12042]: DHCPDISCOVER(br100) fa:16:3e:07:98:11 Aug 6 02:34:56 precise64 dnsmasq-dhcp[12042]: DHCPOFFER(br100) 192.168.100.2 fa:16:3e:07:98:11 However, the DHCPOFFER never makes it back to the VM running on compute1. If I watch the requests using tcpdump on the vboxnet3 interface on my host machine that runs Vagrant (Mac OS X), I can see both the requests and the replies $ sudo tcpdump -i vboxnet3 -n port 67 or port 68 tcpdump: WARNING: vboxnet3: That device doesn't support promiscuous mode (BIOCPROMISC: Operation not supported on socket) tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on vboxnet3, link-type EN10MB (Ethernet), capture size 65535 bytes 22:51:20.694040 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 22:51:20.694057 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 22:51:20.696047 IP 192.168.100.1.67 > 192.168.100.2.68: BOOTP/DHCP, Reply, length 311 22:51:23.700845 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 22:51:23.700876 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 22:51:23.701591 IP 192.168.100.1.67 > 192.168.100.2.68: BOOTP/DHCP, Reply, length 311 22:51:26.705978 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 22:51:26.705995 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 22:51:26.706527 IP 192.168.100.1.67 > 192.168.100.2.68: BOOTP/DHCP, Reply, length 311 But, if I tcpdump on eth2 on compute, I only see the requests, not the replies: root@compute1:~# tcpdump -i eth2 -n port 67 or port 68 tcpdump: WARNING: eth2: no IPv4 address assigned tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes 02:51:20.240672 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 02:51:23.249758 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 02:51:26.258281 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from fa:16:3e:07:98:11, length 280 At this point, I'm stuck. I'm not sure why the DHCP replies aren't making it to the compute node. Perhaps it has something to do with the configuration of the VirtualBox virtual switch/router? Note that eth2 interfaces on both nodes have been set to promiscuous mode.

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  • wireless internet in linux is very very slow... but in windows.... everythnings fine

    - by Cody Acer
    yesterday when i was connecting to our neighbors wifi connection which is the signal strength is below 50%, i cant browse anything... even ping to gateway. 100% packet loss, and sometimes.. i can connect awesomely i can open my facebook account for 15 minutes but after 15min.. connection is extremely slow. but not windows i can surf even the signal str is very poor weird ey??.. root@Emely:~# lspci -knn 00:00.0 Host bridge [0600]: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx DMI Bridge [8086:a010] Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: agpgart-intel 00:02.0 VGA compatible controller [0300]: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller [8086:a011] Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: i915 Kernel modules: i915 00:02.1 Display controller [0380]: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller [8086:a012] Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] 00:1b.0 Audio device [0403]: Intel Corporation NM10/ICH7 Family High Definition Audio Controller [8086:27d8] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel 00:1c.0 PCI bridge [0604]: Intel Corporation NM10/ICH7 Family PCI Express Port 1 [8086:27d0] (rev 02) Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.1 PCI bridge [0604]: Intel Corporation NM10/ICH7 Family PCI Express Port 2 [8086:27d2] (rev 02) Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.2 PCI bridge [0604]: Intel Corporation NM10/ICH7 Family PCI Express Port 3 [8086:27d4] (rev 02) Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.3 PCI bridge [0604]: Intel Corporation NM10/ICH7 Family PCI Express Port 4 [8086:27d6] (rev 02) Kernel driver in use: pcieport Kernel modules: shpchp 00:1d.0 USB controller [0c03]: Intel Corporation NM10/ICH7 Family USB UHCI Controller #1 [8086:27c8] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: uhci_hcd 00:1d.1 USB controller [0c03]: Intel Corporation NM10/ICH7 Family USB UHCI Controller #2 [8086:27c9] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: uhci_hcd 00:1d.2 USB controller [0c03]: Intel Corporation NM10/ICH7 Family USB UHCI Controller #3 [8086:27ca] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: uhci_hcd 00:1d.3 USB controller [0c03]: Intel Corporation NM10/ICH7 Family USB UHCI Controller #4 [8086:27cb] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: uhci_hcd 00:1d.7 USB controller [0c03]: Intel Corporation NM10/ICH7 Family USB2 EHCI Controller [8086:27cc] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: ehci-pci 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev e2) 00:1f.0 ISA bridge [0601]: Intel Corporation NM10 Family LPC Controller [8086:27bc] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: lpc_ich Kernel modules: lpc_ich 00:1f.2 SATA controller [0106]: Intel Corporation NM10/ICH7 Family SATA Controller [AHCI mode] [8086:27c1] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: ahci Kernel modules: ahci 00:1f.3 SMBus [0c05]: Intel Corporation NM10/ICH7 Family SMBus Controller [8086:27da] (rev 02) Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel modules: i2c-i801 05:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11bgn Wireless Network Adapter [14e4:4727] (rev 01) Subsystem: Wistron NeWeb Corp. Device [185f:051a] Kernel driver in use: bcma-pci-bridge Kernel modules: bcma 09:00.0 Ethernet controller [0200]: Marvell Technology Group Ltd. 88E8040 PCI-E Fast Ethernet Controller [11ab:4354] Subsystem: Samsung Electronics Co Ltd Notebook N150P [144d:c072] Kernel driver in use: sky2 Kernel modules: sky2 root@Emely:~# ip addr show 1: lo: mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qdisc pfifo_fast state DOWN qlen 1000 link/ether e8:11:32:2e:a6:fd brd ff:ff:ff:ff:ff:ff 3: wlan0: mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:1b:b1:a9:ac:e0 brd ff:ff:ff:ff:ff:ff inet 192.168.1.108/24 brd 192.168.1.255 scope global wlan0 inet6 fe80::21b:b1ff:fea9:ace0/64 scope link valid_lft forever preferred_lft forever root@Emely:~# ip link show 1: lo: mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eth0: mtu 1500 qdisc pfifo_fast state DOWN qlen 1000 link/ether e8:11:32:2e:a6:fd brd ff:ff:ff:ff:ff:ff 3: wlan0: mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:1b:b1:a9:ac:e0 brd ff:ff:ff:ff:ff:ff root@Emely:~# rfkill list all 0: samsung-wlan: Wireless LAN Soft blocked: no Hard blocked: no 1: samsung-bluetooth: Bluetooth Soft blocked: no Hard blocked: no 2: hci0: Bluetooth Soft blocked: no Hard blocked: no 3: phy0: Wireless LAN Soft blocked: no Hard blocked: no is this a wireless driver issue?

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  • Two network interfaces and two IP addresses on the same subnet in Linux

    - by Scott Duckworth
    I recently ran into a situation where I needed two IP addresses on the same subnet assigned to one Linux host so that we could run two SSL/TLS sites. My first approach was to use IP aliasing, e.g. using eth0:0, eth0:1, etc, but our network admins have some fairly strict settings in place for security that squashed this idea: They use DHCP snooping and normally don't allow static IP addresses. Static addressing is accomplished by using static DHCP entries, so the same MAC address always gets the same IP assignment. This feature can be disabled per switchport if you ask and you have a reason for it (thankfully I have a good relationship with the network guys and this isn't hard to do). With the DHCP snooping disabled on the switchport, they had to put in a rule on the switch that said MAC address X is allowed to have IP address Y. Unfortunately this had the side effect of also saying that MAC address X is ONLY allowed to have IP address Y. IP aliasing required that MAC address X was assigned two IP addresses, so this didn't work. There may have been a way around these issues on the switch configuration, but in an attempt to preserve good relations with the network admins I tried to find another way. Having two network interfaces seemed like the next logical step. Thankfully this Linux system is a virtual machine, so I was able to easily add a second network interface (without rebooting, I might add - pretty cool). A few keystrokes later I had two network interfaces up and running and both pulled IP addresses from DHCP. But then the problem came in: the network admins could see (on the switch) the ARP entry for both interfaces, but only the first network interface that I brought up would respond to pings or any sort of TCP or UDP traffic. After lots of digging and poking, here's what I came up with. It seems to work, but it also seems to be a lot of work for something that seems like it should be simple. Any alternate ideas out there? Step 1: Enable ARP filtering on all interfaces: # sysctl -w net.ipv4.conf.all.arp_filter=1 # echo "net.ipv4.conf.all.arp_filter = 1" >> /etc/sysctl.conf From the file networking/ip-sysctl.txt in the Linux kernel docs: arp_filter - BOOLEAN 1 - Allows you to have multiple network interfaces on the same subnet, and have the ARPs for each interface be answered based on whether or not the kernel would route a packet from the ARP'd IP out that interface (therefore you must use source based routing for this to work). In other words it allows control of which cards (usually 1) will respond to an arp request. 0 - (default) The kernel can respond to arp requests with addresses from other interfaces. This may seem wrong but it usually makes sense, because it increases the chance of successful communication. IP addresses are owned by the complete host on Linux, not by particular interfaces. Only for more complex setups like load- balancing, does this behaviour cause problems. arp_filter for the interface will be enabled if at least one of conf/{all,interface}/arp_filter is set to TRUE, it will be disabled otherwise Step 2: Implement source-based routing I basically just followed directions from http://lartc.org/howto/lartc.rpdb.multiple-links.html, although that page was written with a different goal in mind (dealing with two ISPs). Assume that the subnet is 10.0.0.0/24, the gateway is 10.0.0.1, the IP address for eth0 is 10.0.0.100, and the IP address for eth1 is 10.0.0.101. Define two new routing tables named eth0 and eth1 in /etc/iproute2/rt_tables: ... top of file omitted ... 1 eth0 2 eth1 Define the routes for these two tables: # ip route add default via 10.0.0.1 table eth0 # ip route add default via 10.0.0.1 table eth1 # ip route add 10.0.0.0/24 dev eth0 src 10.0.0.100 table eth0 # ip route add 10.0.0.0/24 dev eth1 src 10.0.0.101 table eth1 Define the rules for when to use the new routing tables: # ip rule add from 10.0.0.100 table eth0 # ip rule add from 10.0.0.101 table eth1 The main routing table was already taken care of by DHCP (and it's not even clear that its strictly necessary in this case), but it basically equates to this: # ip route add default via 10.0.0.1 dev eth0 # ip route add 130.127.48.0/23 dev eth0 src 10.0.0.100 # ip route add 130.127.48.0/23 dev eth1 src 10.0.0.101 And voila! Everything seems to work just fine. Sending pings to both IP addresses works fine. Sending pings from this system to other systems and forcing the ping to use a specific interface works fine (ping -I eth0 10.0.0.1, ping -I eth1 10.0.0.1). And most importantly, all TCP and UDP traffic to/from either IP address works as expected. So again, my question is: is there a better way to do this? This seems like a lot of work for a seemingly simple problem.

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  • VirtualBox - Public Static IP for a Debian Guest on a Dedicated Server

    - by user86296
    Goal: I want to run a Debian-squeeze-Guest in VirtualBox and it's own public static ip. I found tons of threads about this topic, but all in all I'm now trying for 10 hours (reading the manual, the forums, trying to learn about networking concepts & commands) to give a Guest his own public static ip (so that the Guest is similar to a vServer you can order from a hosting company), but wasn't able to. Since I'm a big noob as far as networking stuff is concerned, I'm probably doing something wrong.(please bear with me :-) ) Situation: VirtualBox 4.0.10 (headless no gui) is running on a dedicated Debian-Server, the Guest OS is Debian as well. The server has a static ip and I ordered an additional ip for a VM. Problem description: Upto now I was able to use NAT to access the VM from the outside and to setup an internal network between several Guests and all of this worked very well. When setting NIC 1 to bridged and configuring a public static ip on the guest, the guest was unpingable. (neither from outside, nor from the host) I could connect to the guest via the internal network, from another vm, though. ( VBoxManage controlvm VMGuest nic1 bridged eth0 ) ( configuration attempt of static-ip on the guest '/etc/network/interfaces' is below) Please let me know what I'm doing wrong, or what I can try to get it to work, or if you need more info. I think I've read that with a current VirtualBox-version for bridged networking no special host-configuration is necessary, is that accurate, or might that be the problem? Additional Info Info I got from the hosting company about the additional IP Please note that you can use the IP address only for this server. IP: 46.4.xx.xx Gateway: 46.4.xx.xx Mask: 255.255.255.248 VBoxManage showvminfo VMGuest |less ... NIC 1: MAC: 080027D72F7B, Attachment: Bridged Interface 'eth0', Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0 NIC 2: MAC: 080027B03B75, Attachment: Internal Network 'InternalNet1', Cable connected: on, Trace: off (file: none), Type: Am79C973, Reported speed: 0 Mbps, Boot priority: 0 NIC 3: disabled (...rest is disabled) cat /etc/network/interfaces on the Host-machine # Loopback device: auto lo iface lo inet loopback # device: eth0 auto eth0 iface eth0 inet static address 46.4.xx.xx broadcast 46.4.xx.xx netmask 255.255.255.224 gateway 46.4.xx.xx post-up mii-tool -F 100baseTx-FD eth0 # default route to access subnet up route add -net 46.4.xx.xx netmask 255.255.255.224 gw 46.4.xx.xx eth0 cat /etc/network/interfaces on the Guest-VM # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface allow-hotplug eth0 auto eth0 iface eth0 inet static address 46.4.xx.xx netmask 255.255.255.248 gateway 46.4.xx.xx auto eth1 iface eth1 inet dhcp ifconfig -a on the Guest shows the correct static ip for eth0 but the Guest is unreachable "over eth0" eth0 Link encap:Ethernet HWaddr 08:00:27:d7:2f:7b inet addr:46.4.xx.xx Bcast:46.4.xx.xx Mask:255.255.255.248 inet6 addr: fe80::a00:27ff:fed7:2f7b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:21 errors:0 dropped:0 overruns:0 frame:0 TX packets:69 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1260 (1.2 KiB) TX bytes:3114 (3.0 KiB) eth1 Link encap:Ethernet HWaddr 08:00:27:b0:3b:75 inet addr:192.168.10.3 Bcast:192.168.10.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:feb0:3b75/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:142 errors:0 dropped:0 overruns:0 frame:0 TX packets:92 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:15962 (15.5 KiB) TX bytes:14540 (14.1 KiB) Interrupt:16 Base address:0xd240 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:123 errors:0 dropped:0 overruns:0 frame:0 TX packets:123 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:25156 (24.5 KiB) TX bytes:25156 (24.5 KiB)

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  • linux routing bug?

    - by Balázs Pozsár
    I have been struggling with this not easily reproducible issue since a while. I am using linux kernel v3.1.0, and sometimes routing to a few IP addresses does not work. What seems to happen is that instead of sending the packet to the gateway, the kernel treats the destination address as local, and tries to gets its MAC address via ARP. For example, now my current IP address is 172.16.1.104/24, the gateway is 172.16.1.254: # ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1B:63:97:FC:DC inet addr:172.16.1.104 Bcast:172.16.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:230772 errors:0 dropped:0 overruns:0 frame:0 TX packets:171013 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:191879370 (182.9 Mb) TX bytes:47173253 (44.9 Mb) Interrupt:17 # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 172.16.1.254 0.0.0.0 UG 0 0 0 eth0 172.16.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0 I can ping a few addresses, but not 172.16.0.59: # ping -c1 172.16.1.254 PING 172.16.1.254 (172.16.1.254) 56(84) bytes of data. 64 bytes from 172.16.1.254: icmp_seq=1 ttl=64 time=0.383 ms --- 172.16.1.254 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.383/0.383/0.383/0.000 ms root@pozsybook:~# ping -c1 172.16.0.1 PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data. 64 bytes from 172.16.0.1: icmp_seq=1 ttl=63 time=5.54 ms --- 172.16.0.1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 5.545/5.545/5.545/0.000 ms root@pozsybook:~# ping -c1 172.16.0.2 PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data. 64 bytes from 172.16.0.2: icmp_seq=1 ttl=62 time=7.92 ms --- 172.16.0.2 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 7.925/7.925/7.925/0.000 ms root@pozsybook:~# ping -c1 172.16.0.59 PING 172.16.0.59 (172.16.0.59) 56(84) bytes of data. From 172.16.1.104 icmp_seq=1 Destination Host Unreachable --- 172.16.0.59 ping statistics --- 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms When trying to ping 172.16.0.59, I can see in tcpdump that an ARP req was sent: # tcpdump -n -i eth0|grep ARP tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes 15:25:16.671217 ARP, Request who-has 172.16.0.59 tell 172.16.1.104, length 28 and /proc/net/arp has an incomplete entry for 172.16.0.59: # grep 172.16.0.59 /proc/net/arp 172.16.0.59 0x1 0x0 00:00:00:00:00:00 * eth0 Please note, that 172.16.0.59 is accessible from this LAN from other computers. Does anyone have any idea of what's going on? Thanks. update: replies to the comments below: there are no interfaces besides eth0 and lo the ARP req cannot be seen on the other end, but that's how it should work. the main problem is that an ARP req should not even be sent at the first place the problem persist even if I add an explicit route with the command "route add -host 172.16.0.59 gw 172.16.1.254 dev eth0"

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  • unable to sniff traffic despite network interface being in monitor or promiscuous mode

    - by user65126
    I'm trying to sniff out my network's wireless traffic but am having issues. I'm able to put the card in monitor mode, but am unable to see any traffic except broadcasts, multicasts and probe/beacon frames. I have two network interfaces on this laptop. One is connected normally to 'linksys' and the other is in monitor mode. The interface in monitor mode is on the right channel. I'm not associated with the access point because, as I understand, I don't need to if using monitor mode (vs promiscuous). When I try to ping the router ip, I'm not seeing that traffic show up in wireshark. Here's my ifconfig settings: daniel@seasonBlack:~$ ifconfig eth0 Link encap:Ethernet HWaddr 00:1f:29:9e:b2:89 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Interrupt:16 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:112 errors:0 dropped:0 overruns:0 frame:0 TX packets:112 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:8518 (8.5 KB) TX bytes:8518 (8.5 KB) wlan0 Link encap:Ethernet HWaddr 00:21:00:34:f7:f4 inet addr:192.168.1.116 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::221:ff:fe34:f7f4/64 Scope:Link UP BROADCAST RUNNING MTU:1500 Metric:1 RX packets:9758 errors:0 dropped:0 overruns:0 frame:0 TX packets:4869 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:3291516 (3.2 MB) TX bytes:677386 (677.3 KB) wlan1 Link encap:UNSPEC HWaddr 00-02-72-7B-92-53-33-34-00-00-00-00-00-00-00-00 UP BROADCAST NOTRAILERS PROMISC ALLMULTI MTU:1500 Metric:1 RX packets:112754 errors:0 dropped:0 overruns:0 frame:0 TX packets:101 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:18569124 (18.5 MB) TX bytes:12874 (12.8 KB) wmaster0 Link encap:UNSPEC HWaddr 00-21-00-34-F7-F4-00-00-00-00-00-00-00-00-00-00 UP RUNNING MTU:0 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) wmaster1 Link encap:UNSPEC HWaddr 00-02-72-7B-92-53-00-00-00-00-00-00-00-00-00-00 UP RUNNING MTU:0 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Here's my iwconfig settings: daniel@seasonBlack:~$ iwconfig lo no wireless extensions. eth0 no wireless extensions. wmaster0 no wireless extensions. wlan0 IEEE 802.11bg ESSID:"linksys" Mode:Managed Frequency:2.437 GHz Access Point: 00:18:F8:D6:17:34 Bit Rate=54 Mb/s Tx-Power=27 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality=68/70 Signal level=-42 dBm Noise level=-69 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 wmaster1 no wireless extensions. wlan1 IEEE 802.11bg Mode:Monitor Frequency:2.437 GHz Tx-Power=27 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality:0 Signal level:0 Noise level:0 Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 Here's how I know I'm on the right channel: daniel@seasonBlack:~$ iwlist channel lo no frequency information. eth0 no frequency information. wmaster0 no frequency information. wlan0 11 channels in total; available frequencies : Channel 01 : 2.412 GHz Channel 02 : 2.417 GHz Channel 03 : 2.422 GHz Channel 04 : 2.427 GHz Channel 05 : 2.432 GHz Channel 06 : 2.437 GHz Channel 07 : 2.442 GHz Channel 08 : 2.447 GHz Channel 09 : 2.452 GHz Channel 10 : 2.457 GHz Channel 11 : 2.462 GHz Current Frequency=2.437 GHz (Channel 6) wmaster1 no frequency information. wlan1 11 channels in total; available frequencies : Channel 01 : 2.412 GHz Channel 02 : 2.417 GHz Channel 03 : 2.422 GHz Channel 04 : 2.427 GHz Channel 05 : 2.432 GHz Channel 06 : 2.437 GHz Channel 07 : 2.442 GHz Channel 08 : 2.447 GHz Channel 09 : 2.452 GHz Channel 10 : 2.457 GHz Channel 11 : 2.462 GHz Current Frequency=2.437 GHz (Channel 6)

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  • Windows Server 2012 Migration (DNS/AD DS Standard Eval to Essentials OEM) P2V -> Do I need a Secondary Domain Controller during migration?

    - by Aubrey Robertson
    This is my first post on this exchange (although not my first on stack exchange), so please have patience. I am a 3rd year student intern, and I have been tasked with virtualizing the server systems at the company I work for. I have come a long way, and I am almost ready to install the VM Server in migration mode. Here is some information: Source Server: Windows Server 2012 Standard Evaluation DNS Server (local only) Advanced Directory Domain Services File and Storage stuff A few other server roles Destination Server: Windows Server 2012 Essentials OEM (Hyper-V client) Running under a temporary Hyper-V host (will migrate the Hyper-V host back to the old machine after the original server is virtualized as a client). Sitting currently at the "Select Installation Mode" screen. I have been following the guides on Microsoft tech net, and today I spent most of the day getting rid of issues in the Best Practices Analyser on the source machine. I have 3 remaining issues (which are all related): ERROR: DNS: DNS servers on Ethernet (adapter name) should include the loopback address, but not as the first entry (flavour text indicates that, during migration, the DNS server may not be found) WARNING: All domains should have at least two domain controllers for redundancy. WARNING: DNS: Ethernet should be configured to use both a preferred and an alternate DNS Server. All of these issues can be resolved by deploying a secondary domain controller, but I have never done that before (see my concerns below). The main issue here that I am concerned with for installing in migration mode is the FIRST one (the error). If I try and set-up the new server deployment, and the adapter domain controller is listed as localhost, then this may cause the installation to fail. (at least, this is what the Microsoft documentation suggests). But I do not have another IP address to enter here as I have no other local domain controllers. So I did the first obvious thing that came to my mind, and tried to use Google DNS servers as my alternates. That did not work because they couldn't recognize other computers in the "forest". Now I'm no expert when it comes to DNS, so please forgive my ignorance. This DNS server is concerned only with Active Directory stuffs for the local network. If I go ahead with migration, and it fails, then I will just have to go ahead and install a secondary DNS server I suppose. The problem I have here is that I am limited by the amount of Windows Server keys I have available (I have 2); however, I do have access to a Linux box running Debian Wheezy that I set-up two weeks ago as a Mantis server. I could install Windows Server 2012 as a secondary DNS (I think) in a VM and use that, but then it seems like I will be wasting time, and probably the Windows key too, and if there's another way to do it with Linux that would be much better. Even better still, do I even need a secondary DNS server for migration at all? The hints said that during migration the original machine "might" not be found. Thank you for your time and consideration.

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  • IP address reuse on macvlan devices

    - by Alex Bubnoff
    I'm trying to create easy to use and possibly simple testing environment for some product and got some strange behaviour of macvlan's. What I'm trying to achieve: make a toolset for one-line start/stop of lxc containers(via docker) bound to external ip(I have enough of it on host machine). So, I'm doing something like this: docker run -d -name=container_name container_image pipework eth1 container_name ip/prefix_len@gateway and pipework here does this: GUEST_IFNAME=ph$NSPID$eth1 ip link add link eth1 dev $GUEST_IFNAME type macvlan mode bridge ip link set eth1 up ip link set $GUEST_IFNAME netns $NSPID ip netns exec $NSPID ip link set $GUEST_IFNAME name eth1 ip netns exec $NSPID ip addr add $IPADDR dev eth1 ip netns exec $NSPID ip route delete default ip netns exec $NSPID ip link set eth1 up ip netns exec $NSPID ip route replace default via $GATEWAY ip netns exec $NSPID arping -c 1 -A -I eth1 $IPADDR And it works for first time per IP. But for second time and later packets for containers IP isn't getting into container, while all configuration seem fine. So it looks like this: External machine ? ping 212.76.131.212 ....silence.... Host machine root@ubuntu:~# ip link show eth1 2: eth1: mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:15:17:c9:e1:c9 brd ff:ff:ff:ff:ff:ff root@ubuntu:~# ip addr show eth1 2: eth1: mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:15:17:c9:e1:c9 brd ff:ff:ff:ff:ff:ff root@ubuntu:~# tcpdump -v -i eth1 icmp tcpdump: WARNING: eth1: no IPv4 address assigned tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes 00:00:46.542042 IP (tos 0x0, ttl 60, id 9623, offset 0, flags [DF], proto ICMP (1), length 84) 5.134.221.98 212.76.131.212: ICMP echo request, id 6718, seq 2345, length 64 00:00:47.549969 IP (tos 0x0, ttl 60, id 9624, offset 0, flags [DF], proto ICMP (1), length 84) 5.134.221.98 212.76.131.212: ICMP echo request, id 6718, seq 2346, length 64 00:00:48.558143 IP (tos 0x0, ttl 60, id 9625, offset 0, flags [DF], proto ICMP (1), length 84) 5.134.221.98 212.76.131.212: ICMP echo request, id 6718, seq 2347, length 64 00:00:49.566319 IP (tos 0x0, ttl 60, id 9626, offset 0, flags [DF], proto ICMP (1), length 84) 5.134.221.98 212.76.131.212: ICMP echo request, id 6718, seq 2348, length 64 00:00:50.573999 IP (tos 0x0, ttl 60, id 9627, offset 0, flags [DF], proto ICMP (1), length 84) 5.134.221.98 212.76.131.212: ICMP echo request, id 6718, seq 2349, length 64 ^C 5 packets captured 5 packets received by filter 0 packets dropped by kernel 1 packet dropped by interface Host machine, netns of container root@ubuntu:~# ip netns exec 32053 ip link show eth1 48: eth1@if2: mtu 1500 qdisc noqueue state UNKNOWN link/ether b2:12:f7:cc:a1:9d brd ff:ff:ff:ff:ff:ff root@ubuntu:~# ip netns exec 32053 ip addr show eth1 48: eth1@if2: mtu 1500 qdisc noqueue state UNKNOWN link/ether b2:12:f7:cc:a1:9d brd ff:ff:ff:ff:ff:ff inet 212.76.131.212/29 scope global eth1 inet6 fe80::b012:f7ff:fecc:a19d/64 scope link valid_lft forever preferred_lft forever root@ubuntu:~# ip netns exec 32053 tcpdump -v -i eth1 icmp tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes ....silence.... ^C 0 packets captured 0 packets received by filter 0 packets dropped by kernel So, can anyone say, what can it be? Can this be caused by not a bug in macvlan implementation? Is there any tools I can use to debug that configuration?

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  • Neighbour table overflow on Linux hosts related to bridging and ipv6

    - by tim
    Note: I already have a workaround for this problem (as described below) so this is only a "want-to-know" question. I have a productive setup with around 50 hosts including blades running xen 4 and equallogics providing iscsi. All xen dom0s are almost plain Debian 5. The setup includes several bridges on every dom0 to support xen bridged networking. In total there are between 5 and 12 bridges on each dom0 servicing one vlan each. None of the hosts has routing enabled. At one point in time we moved one of the machines to a new hardware including a raid controller and so we installed an upstream 3.0.22/x86_64 kernel with xen patches. All other machines run debian xen-dom0-kernel. Since then we noticed on all hosts in the setup the following errors every ~2 minutes: [55888.881994] __ratelimit: 908 callbacks suppressed [55888.882221] Neighbour table overflow. [55888.882476] Neighbour table overflow. [55888.882732] Neighbour table overflow. [55888.883050] Neighbour table overflow. [55888.883307] Neighbour table overflow. [55888.883562] Neighbour table overflow. [55888.883859] Neighbour table overflow. [55888.884118] Neighbour table overflow. [55888.884373] Neighbour table overflow. [55888.884666] Neighbour table overflow. The arp table (arp -n) never showed more than around 20 entries on every machine. We tried the obvious tweaks and raised the /proc/sys/net/ipv4/neigh/default/gc_thresh* values. FInally to 16384 entries but no effect. Not even the interval of ~2 minutes changed which lead me to the conclusion that this is totally unrelated. tcpdump showed no uncommon ipv4 traffic on any interface. The only interesting finding from tcpdump were ipv6 packets bursting in like: 14:33:13.137668 IP6 fe80::216:3eff:fe1d:9d01 > ff02::1:ff1d:9d01: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:9d01, length 24 14:33:13.138061 IP6 fe80::216:3eff:fe1d:a8c1 > ff02::1:ff1d:a8c1: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:a8c1, length 24 14:33:13.138619 IP6 fe80::216:3eff:fe1d:bf81 > ff02::1:ff1d:bf81: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:bf81, length 24 14:33:13.138974 IP6 fe80::216:3eff:fe1d:eb41 > ff02::1:ff1d:eb41: HBH ICMP6, multicast listener reportmax resp delay: 0 addr: ff02::1:ff1d:eb41, length 24 which placed the idea in my mind that the problem maybe related to ipv6, since we have no ipv6 services in this setup. The only other hint was the coincidence of the host upgrade with the beginning of the problems. I powered down the host in question and the errors were gone. Then I subsequently took down the bridges on the host and when i took down (ifconfig down) one particularly bridge: br-vlan2159 Link encap:Ethernet HWaddr 00:26:b9:fb:16:2c inet6 addr: fe80::226:b9ff:fefb:162c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:120 errors:0 dropped:0 overruns:0 frame:0 TX packets:9 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:5286 (5.1 KiB) TX bytes:726 (726.0 B) eth0.2159 Link encap:Ethernet HWaddr 00:26:b9:fb:16:2c inet6 addr: fe80::226:b9ff:fefb:162c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1801 errors:0 dropped:0 overruns:0 frame:0 TX packets:20 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:126228 (123.2 KiB) TX bytes:1464 (1.4 KiB) bridge name bridge id STP enabled interfaces ... br-vlan2158 8000.0026b9fb162c no eth0.2158 br-vlan2159 8000.0026b9fb162c no eth0.2159 The errors went away again. As you can see the bridge holds no ipv4 address and it's only member is eth0.2159 so no traffic should cross it. Bridge and interface .2159 / .2157 / .2158 which are in all aspects identical apart from the vlan they are connected to had no effect when taken down. Now I disabled ipv6 on the entire host via sysctl net.ipv6.conf.all.disable_ipv6 and rebooted. After this even with bridge br-vlan2159 enabled no errors occur. Any ideas are welcome.

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