[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
>From what I am observing here, the IPV6 problem is not the sole cause of slow lookups and connection speed. Despite turning off IPV6, running my own name server (even a local caching one), modifying /etc/nsswitch.conf, tweaking settings in ethtool, etc. etc. etc. I still get stalls and failed connections so often that the distribution is on the verge of unusable. To reproduce this problem open 15 tabs or so in firefox. close firefox. Open it again and open another network app like Thunder bird at the same time. More often than not many tabs will fail to load and you'll get a failed to connect error from Thunderbird. As has been reported, this does not happen, for instance, in WinXP running in VMware on the same physical machine. I am behind a D-Link DI-707 switch. Unfortunately, it looks like I am going to have to bail on Ubuntu. It's too bad. The distribution has a lot of promise. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Laurent As I mentioned, I have turned off ipv6 in grub: r...@humility:~# ip -6 addr r...@humility:~# r...@humility:~# ip -6 route 172.16.38.0/24 dev vmnet8 proto kernel scope link src 172.16.38.1 192.168.194.0/24 dev vmnet1 proto kernel scope link src 192.168.194.1 192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.5 169.254.0.0/16 dev eth0 scope link metric 1000 default via 192.168.0.1 dev eth0 metric 100 I am running VMWare Workstation 7 on this machine. I run my own nameserver which is on a CentOS 5 machine on the other side of a DLink DI-707 firewall gadget. I would be more than happy to run any tests to help track this down. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
I can confirm that there is something else, beyond IPV6 lookups, that is causing timeouts. Kubuntu 9.10 with "libc6-i686 2.10.1-0ubuntu16 (i386)" which, if I'm not mistaken, contains the IPV6 fix. Dell Nseries desktop box. Completely stock. Using fixed IP behind a D-Link 707 consumer grade firewall. DNS server running on a CentOS 5 box on the other side of the firewall. IPV6 disabled in /etc/default/grub using GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1 quiet splash" IPV6 disabled in firefox as well. Regardless of whether I use a local caching nameserver, pdns-recursor, or a name server on a CentOS 5 box, the timeout phenomenon is the same. >From a gut feel point of view, I'd say it's worse when using the local caching nameserver. Running WinXP in VMWare Workstation 7 on the same physical machine with no timeouts. (i.e. While it's timing out in firefox I switch into XP and pull the same page. Comes up instantly.) My feeling is we're dealing with some kind of race condition in the resolver library because it happens when doing a number of simultaneous DNS requests. Open 20 or so tabs in firefox to various websites with varying load times. Close firefox. Reopen firefox and at the same time open Thunderbird. In this scenario Thunderbird will timeout 100% of the time as will the majority of tabs in firefox. It's intermittent. In FF, I can have one tab that's loading and other that's timing out. Sometimes it will pull the main html page but timeout on graphics or CSS. I would like to be able to run Kubuntu instead of having to fallback to CentOS 5. I am willing to lend a hand to track this down if you would like to give me some tests to run. I can reproduce this problem consistently. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
My bad. It looks like what I described above is covered by this bug: https://bugs.launchpad.net/ubuntu/+source/nss-mdns/+bug/94940 Editing /etc/nsswitch.conf and changing hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4 to hosts: files dns looks like it "fixes" this issue. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Laurent Ok, I spent some more time researching this, playing with various scenarios. 1. Fedore Core 12 running in VMWare exhibits the same problem as Ubuntu 9.10 running natively. 2. WinXP running in VMWare does /not/ exhibit the problem. 3. Cent OS 5.4 running in VMWare does exhibit the problem. Something I was not expecting. 4. Ubuntu 8.04 did /not/ exhibit this problem. It started with 8.10 and appeared to be much worse in 9.10. Based on some discussions that I remember reading (but no longer have a link to) I decided to try to upgrade the firmware on my DLink 707 firewall gadget to version 2.57 from version 2.51. It's too early to tell for sure, but my initial feeling is that network performance is much improved. My standard test of loading multiple large pages simultaneously is not causing the problem. If this turns out to be the "fix", the question would be why did Ubuntu 8.04 work flawlessly and later versions have problems? -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Laurent yes. /ALL/ network access regardless of application is affected. Please re-read the report I wrote. Yes, this has nothing to do with the IPv6 DNS lookup problem. IPV6 record lookup was one issue that would cause the slow connections so many people are experiencing. My point is that while the IPv6 lookup issue has been resolved, it is not the only cause of the slow dns lookup/connection symptoms people are experiencing. As I have said, IPV6 is /disabled/ on my machine via grub. IPV6 is disabled in firefox. IPV6 IS NOT THE SOLE REASON FOR SLOW DNS AND NETWORK CONNECTION IN UBUNTU. i have verified this here. Maybe it should be listed as a separate bug, but none of the other bugs I have found (of which there are many) seem to match the symptoms I'm seeing here exactly. Slow dns lookups. DNS lookup failure 30% of the time or so. Connection failure 30% of the time or so. Extremely slow net connectivity over a wired connections. I've tried every combination of work around I could find on the net to no avail. Then I upgraded the firmware on my DI-707 router and suddenly the problem disappears. The confusing thing is that Ubuntu 8.04, WinXp and EVERY SINGLE DISTRIBUTION BEFORE had no issue with this router. It seems to be restricted to recent 2.6 kernels. I had read somewhere, I'm sorry I have forgotten where, that there was some TCP/IP standards issue that someone had decided to implement too strictly in recent kernels which caused connections through many legacy routers/switches/firewalls to fail (which is why I tried the firmware upgrade). At this point, for me, the problem seems to be solved, but I have the feeling that there are many Ubuntu users out there that are still suffering from slow/failing dns lookups and the IPV6 issue does not explain all of them. There is still some network level problem. But like I said, the firmware upgrade on my DI-707 seems to have worked around whatever problem Ubuntu has. I'm reporting this in an attempt to be helpful; too often in my own software business customers who are running into trouble with our software simply don't report their experiences so we have no idea that there's a problem. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Laurent Yes, I was thinking the same thing since it's now fixed for me. However, if you do some searches, even in the Ubuntu forums I think, you'll find dozens if not hundreds of posts from people saying they turned off IPV6 but still had slow lookups/connectivity. There was one thread somewhere where it was mentioned that this was due to Ubuntu/Linux now implementing some standard (I don't know which one) more rigidly than many router/switch manufacturers. That was the reason I thought to upgrade the firmware in the DI-707. Doing a quick search I find: http://superuser.com/questions/67686/internet-very-slow-when-upgrading- to-ubuntu-9-10 (3rd comment) http://ubuntuforums.org/showthread.php?p=8758456 (5th post) -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Laurent No. Wired connection exclusively. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Ricardo Fernández As I mention above, in my case, after disabling IPV6, I still had the same symptoms. Terribly long delays making any kind of network connections (all wired). I noticed here that it seemed to be related to making more than one network connection at a time. Based on forum posts elsewhere, I upgraded the firmware on my D-Link 707 switch/firewall and then suddenly all network problems disappeared. Of course, CentOS, WinXP, Win2K and Ubuntu 8.04 never had a problem with the router, so I'm not sure why this fixed the issue. But unfortunately, I've wasted too much time on Ubuntu 9.10 problems. It's been by far the buggiest least reliable error prone distribution I've ever come across (been developing software using Linux professionally since early 1993). This is also the very first time I've been unable to find good information on how work around issues that come up despite having put in some serious effort. (Sound, anyone?) It's open source after all and I've offered to help track these issues down, but got no useful response. So I've bailed. I'm running Fedora Core 12 now. Everything works as it should. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Hillshum re-read what I wrote. Disabling IPV6 /does not/ resolve the symtpom. But for me it no longer matters. I've bailed and switched to Fedora Core 12. It works. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 417757] Re: [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups
@Ricardo: Amen. Ubuntu is a nice "end-user-friendly" distribution. I respect what they are trying to do. But there comes a point where bailing is the only sensible option. Fedora Core 12 works like a champ. Networking works. Sound works. Package management works. Java works. OpenOffice works. etc. And I've noticed the same thing you have. The quality of technical posts for Fedora Core is definitely much higher than what I've seen in Ubuntu. I'm not sure why. It's all Linux after all. I guess Fedora attracts a more technical crowd and they seem, at least for the moment, to be much more focused on solving problems. -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 433972] Re: Internet ping very slow on Karmic Koala
I am also seeing random network slowdowns on my Dell N-Series using a wired connection. (Kubuntu 9.10, all updates applied) It does not seem to affect local connections (e.g. connecting to Apache on the same box, which was not the case with the ipv6 bug and nsswitch.conf issue ). Cataloging my experiences here: http://yml.com/fv-b-1-545/Slow-DNS- Lookups-in-Ubuntu-9-10--Karmic-Koala-.html I have disabled ipv6 and edited nsswitch.conf which improved performance, but I am still seeing very long connection delays and random slowdowns in network connections. Running WinXp in VMWare on the very same machine shows no such slowdowns, thereby eliminating any questions about the network. My feeling is this is a race condition. It seems to occur most frequently when more than one process (or thread) attempts to make a network connection (e.g. load up a bunch of tabs in firefox simultaneously and at the same time pull mail using Thunderbird) If there are any tests I can run to help track this down, please let me know. -- Internet ping very slow on Karmic Koala https://bugs.launchpad.net/bugs/433972 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
