Re: [SLE] Why Very Slow DNS on 8.2, But Not on WinXP?
Anyone know why name resolution using my cable provider's nameservers is impossibly slow on a standard untweaked 8.2 install, but quite fast with WinXP on the same machine, same provider, same nameservers?
I see the same slowness whether or not my firewall is running, and whether or not I'm running a local cacheing nameserver.
I found the same problem with Mozilla-family browsers using 8.2. Extensive googling finally turned up http://bugzilla.mozilla.org/show_bug.cgi?id=70213 and http://bugzilla.mozilla.org/show_bug.cgi?id=135724#c24. Briefly 1) these browsers lack reentrant/async DNS lookup, so a site that requires multiple DNS lookups (perhaps for ads) won't load until each has returned. 2) Suse 8.2 specifically turns on IPv6, and some servers can't cope with these requests. You don't say which cache you used, but I suggest you try Squid, which caches (inter alia) the DNS information. For me, this makes mozilla-based browsers like Firebird work as fast as IE. As far as I recall, I just installed it as it came, without any configuration (though you do have to tell your browser to use it as a proxy, localhost port 3128, and you may have to adjust your firewall). The other solution is to use Opera, which worked at full speed on my system. Perhaps worth trying, just to prove that this *is* the problem, though the choice of ads or cash made me go for the first method. Hope this helps. David Hart
suse@sillwood-acre.co.uk wrote:
I found the same problem with Mozilla-family browsers using 8.2. Extensive googling finally turned up
http://bugzilla.mozilla.org/show_bug.cgi?id=70213 and http://bugzilla.mozilla.org/show_bug.cgi?id=135724#c24.
Thanks, that is interesting, especially the second URL. It mirrors my experience, expecially with non-Mozilla browsers. Appreciate your comment on running squid to cache DNS (I set up bind as a cacheing server), but a cache can only retain addresses that have already been resolved. Any new lookups won't be affected. The thing that makes me think something else is going on here is the fact that I ran SuSe on my DSL account without these problems showing up. When I switched to cable, the slow DNS was apparent immediately.
Thanks, that is interesting, especially the second URL. It mirrors my experience, expecially with non-Mozilla browsers.
Appreciate your comment on running squid to cache DNS (I set up bind as a cacheing server), but a cache can only retain addresses that have already been resolved. Any new lookups won't be affected.
I'm no expert, but I don't think it's just that it works as a cache, more that it can manage to do several parallel lookups. Whatever the reason, it works.
The thing that makes me think something else is going on here is the fact that I ran SuSe on my DSL account without these problems showing up. When I switched to cable, the slow DNS was apparent immediately.
I'm told that some ISPs do their own proxying. Perhaps you switched to one that doesn't. It's not DSL that's the reason; I had my problem using DSL, but I know of someone who was fine with cable. Regards David Hart
** Reply to message from wgerrard <wgerrard@nc.rr.com> on Fri, 26 Sep 2003 17:36:09 -0400
The thing that makes me think something else is going on here is the fact that I ran SuSE on my DSL account without these problems showing up. When I switched to cable, the slow DNS was apparent immediately.
If it makes you feel any better, I have had the same problems with a DSL account that is 3 years running without problems. I have tried with and without my router. Everything is slow. BTW, when I do traceroute to my ISP's nameservers, even with 100 hops, it never gets there. Just an endless list of "* * *", but never a resolution to the nameserver IP. Any thoughts on that one. Ed Harrison
On Sunday 28 September 2003 01:50, Ed Harrison wrote:
** Reply to message from wgerrard <wgerrard@nc.rr.com> on Fri, 26 Sep 2003 17:36:09 -0400
The thing that makes me think something else is going on here is the fact that I ran SuSE on my DSL account without these problems showing up. When I switched to cable, the slow DNS was apparent immediately.
If it makes you feel any better, I have had the same problems with a DSL account that is 3 years running without problems.
I have tried with and without my router. Everything is slow.
BTW, when I do traceroute to my ISP's nameservers, even with 100 hops, it never gets there. Just an endless list of "* * *", but never a resolution to the nameserver IP.
They could be blocking traceroutes, or perhaps even ICMP packets in general?! Can you ping it?
** Reply to message from Anders Johansson <andjoh@rydsbo.net> on Sun, 28 Sep 2003 01:54:46 +0200
They could be blocking traceroutes, or perhaps even ICMP packets in general?! Can you ping it?
Yes, ping works fine, with good results on 2 of 6 nameservers; the other 4 take almost twice as long. FTP is also up to speed, 70-80 kB/sec. http is what is so slow. Ed Harrison
On Saturday 27 September 2003 18:41, Ed Harrison wrote:
** Reply to message from Anders Johansson <andjoh@rydsbo.net> on Sun, 28 Sep 2003 01:54:46 +0200
They could be blocking traceroutes, or perhaps even ICMP packets in general?! Can you ping it?
Yes, ping works fine, with good results on 2 of 6 nameservers; the other 4 take almost twice as long.
FTP is also up to speed, 70-80 kB/sec. http is what is so slow.
Ed Harrison
Your system will only use name servers one at a time, if the first times out or is unreachable it will then (and only then) go to the next. So get rid of the slow ones and use only 1 or 2 fast ones. -- _____________________________________ John Andersen
On 09/28/2003 10:41 AM, Ed Harrison wrote:
** Reply to message from Anders Johansson <andjoh@rydsbo.net> on Sun, 28 Sep 2003 01:54:46 +0200
They could be blocking traceroutes, or perhaps even ICMP packets in general?! Can you ping it?
Yes, ping works fine, with good results on 2 of 6 nameservers; the other 4 take almost twice as long.
FTP is also up to speed, 70-80 kB/sec. http is what is so slow.
Are you POSITIVE they are not running an http proxy, that maybe is auto detected with IE in Windows, but needs to be entered in your Linux system? It sure sounds like that to me. -- Joe Morris New Tribes Mission Email Address: Joe_Morris@ntm.org Web Address: http://www.mydestiny.net/~joe_morris Registered Linux user 231871 God said, I AM that I AM. I say, by the grace of God, I am what I am.
On Fri, 2003-09-26 at 13:36, wgerrard wrote:
suse@sillwood-acre.co.uk wrote:
I found the same problem with Mozilla-family browsers using 8.2. Extensive googling finally turned up
http://bugzilla.mozilla.org/show_bug.cgi?id=70213 and http://bugzilla.mozilla.org/show_bug.cgi?id=135724#c24.
Thanks, that is interesting, especially the second URL. It mirrors my experience, expecially with non-Mozilla browsers.
Appreciate your comment on running squid to cache DNS (I set up bind as a cacheing server), but a cache can only retain addresses that have already been resolved. Any new lookups won't be affected.
The thing that makes me think something else is going on here is the fact that I ran SuSe on my DSL account without these problems showing up. When I switched to cable, the slow DNS was apparent immediately.
I find that using dnscache speeds things a lot. See http://cr.yp.to/djbdns/run-cache.html It's excellent and easy to get up and running. Dee
Another problem I found on my system that produced similar slow down effects was related to having 2 network interfaces. I have an ethernet card, and a USB wireless connection, and by mistake I had got both active on the same subnet, but the ethernet was not woking due to lack of a connecting cable. It is quite impressive that packets got out at all, but each new connection took some time to start up. Hope my mistakes help someone. David On Friday 26 September 2003 9:53 pm, suse@sillwood-acre.co.uk wrote:
Anyone know why name resolution using my cable provider's nameservers is impossibly slow on a standard untweaked 8.2 install, but quite fast with WinXP on the same machine, same provider, same nameservers?
david stevenson wrote:
Another problem I found on my system that produced similar slow down effects was related to having 2 network interfaces. I have an ethernet card, and a USB wireless connection, and by mistake I had got both active on the same subnet, but the ethernet was not woking due to lack of a connecting cable. It is quite impressive that packets got out at all, but each new connection took some time to start up. Hope my mistakes help someone. David
That may well have been my problem, as well. My motherboard has an onboard card which is not well supported in Linux, so I use a RealTek in a PCI slot for my cable internet connection. I'd enabled the onboard card for a test and forgotten to disable it. Once I did that, my DNS woes went away. So, the lesson is: If you aren't going to use a piece of hardware, tell your BIOS to disable it.
participants (9)
-
Anders Johansson -
billg -
david stevenson -
Ed Harrison -
Joe Morris (NTM) -
John Andersen -
suse＠sillwood-acre.co.uk -
W.D. McKinney -
wgerrard