Freddy Freeloader wrote:
Joe Hart wrote:Try giving your router a hard reboot. I once had a situation where one machine on my home lan could not send and receive email but all others could. The fix after many hours of troubleshooting: A hard reboot on my elcheapo home router. I did that only out of frustration after having looked into everything else I could think of.-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 A. Ben Hmeda wrote:Marty wrote:A. Ben Hmeda wrote:I have searched ubuntu forums to no avail. My network connection hasslowed down considerably since I installed Ubuntu Dapper (6.06.1 LTS) I have disabled ipv6 in /etc/aliases and Firefox, still slow by about 50%.My machine AMDSMP is dual boot w2k/ubuntu 6.06.1 LTS (2xAthlon 2000+ 512RAM), network is at full speed with win2k and Fedora Core 5 (now deleted) on this machine.I have another Ubuntu 6.06.1 LTS machine SERVER (2xP3-500 256RAM) and aWin2k KIDPC (P3-866 512RAM) on the same home network that do not have this problem with the network slowdowns. My benchmark is http://www.testmy.net/ website. Every machine on the network has been tested separately, while other machines were turned off. Didn't matter whether the connection was static or dhcp.I have also noticed slowdowns (high latency) while playing on-line gameslike bzflag My /etc/network/interfaces : auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 192.168.1.2 netmask 255.255.255.0 gateway 192.168.1.1 ifconfig output: eth0 Link encap:Ethernet HWaddr 00:04:5A:9A:8C:6Einet addr:192.168.1.2 Bcast:192.168.1.255 Mask:255.255.255.0UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:46508 errors:0 dropped:0 overruns:0 frame:0 TX packets:31020 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:43829777 (41.7 MiB) TX bytes:4368831 (4.1 MiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:9 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:472 (472.0 b) TX bytes:472 (472.0 b) What went wrong?Since You are omitting some crucial details, such as the details of your LAN and your internet connection, for the purposes of this message I will assume that your local LAN speed vastly exceeds the speed of your internet connection and you are using at least 100Mb ethernet (i.e.the typical case). Please correct me if I'm wrong. First I would determine if you have local throughput reduction to the machine in question. You could try testing the throughput between machines. Unless you are using gigabit, these tests should easily saturate your local LAN and leave no doubt about the integrity of the local LAN. If it turns out to be an ethernet issue, then given the lack of RX errors on your system, I would suspect a problem on the TX side, either in the cable or the hub/switch/router on the other end. 100mb ethernet uses two twisted pairs of wires, and problem on only the TX pair would be typically caused by a bad connection or a miswired cable(e.g. incorrectly pairing the conductors in a hand-crimped cable). Another cause is damage to RJ-45 sockets caused by plugging RJ-11 orRJ-14 plugs into RJ-45 sockets. This can bend and permanently damage some of the conductors in RJ-45 sockets. If you find that it's not a physical layer (ethernet) issue, then it's probably an IP stack or applications bug, which would make it an extremely rare and interesting problem. I'm not a developer, but Ithink the developers would be be very interested in such a problem. Incidently I think you can disregard the claim, from another listmember, that this is not a Debian issue. Since Ubuntu is based on Debian, any problem there could very easily apply to Etch, the next stable Debian release.I have an Internet router for sharing cable Internet connection. 3 PCs plugged into this router, class C network, I think. All with static IPs 192.168.1.2,3 and 4. Gateway (router) is 192.168.1.1 DNS is my ISP's 64.71.255.198 I am using 100Mb Ethernet and 10/100Mb router. My Internet connection speed is only 1Mbps (max) My internet download speeds range from 90kB/s to 114kB/s. Under Ubuntu, they crawl at 15kB/s to 25kB/s max! under static IP setup or dhcp setup. The machine with the problem is my AMDSMP. I have had absolutely no problem with network speed (internal and external) until I installed Dapper. As it is now, it is a dual booting machine (win2k and ubuntu) Previously, it ran Debian Sarge, Fedora Core 4 and 5, alongside win2k without any problems. Presently, my network speed is fine under windows, was fine under Sarge, Fedora 4 and 5 on the same machine, except for ubuntu. As I was poking around, trying to figure this out, I noticed that network speed is drastically improved, back to 90kB to 114kB under Ubuntu when, in GNOME, I open the System>>Administration>>Networking and just click OK, without actually changing anything! This makes no sense to me and I have no explanation for it, it certainly does not change the content in my /etc/network/interfaces but I was able to duplicate the steps with same results every time. Is the System>>Administration>>Networking>>OK the same as /etc/init.d/networking restart? Thanks for your helpHave you considered trying something other than Ubuntu? There are many other GNU/Linux distributions that work (and some much better). Ubuntu may be popular, but that doesn't make it the best. Same can be said with the current industry leader's operating system. If you want to use Debian, we can help you. If you want to try something else, take a look at http://distrowatch.com and have a look at the hundreds of choices. Interesting that your network problem magically fixes itself when you try to configure it and do nothing. Is there a ghost in the machine? Joe - -- Registerd Linux user #443289 at http://counter.li.org/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFF/OnViXBCVWpc5J4RAtrBAKDJqqcgsGJPBFNm70Nh7mHY55OHpQCgwqM2 M/4yK4rh/V+zepXrYIIK8Pg= =hCCu -----END PGP SIGNATURE-----I've never figured out why that router would block one, or both, of the ports associated with email to only one address on my lan, but it did. Have you tried blacklisting the ipv6 module to see if that helps? IPv6 will sometimes really slow down apparent network performance on my machines, and a little Googling on the subject of poor network performance says this happens to be an issue that other people running Ubuntu have run into.I would also try using a packet sniffer to see if I could find a pattern of retransmits from lost packets. The last thing I would try is to replace the nic with another one just to see if the problem happens with different hardware.
I have reset my cheap router several times during my bouts with ubuntu. The thing is, it never happened with any other distro, including the latest, Sarge and Fedora 5 (a distro that I only ditched last month). I have no more PCI slots, my NIC is a USB adapter using the pegasus kernel module and IPv6 is blacklisted.
I will try your suggestion, perhaps I'll be able to sniff the ghost in my machine.