Search Again: Re: DNS - site not visible everywhere From: Men & Mice Support Date: Thursday, September 7, 2000 Time: 1:27:36 am At 1:17 AM -0700 9/7/00, Aaron Lynch wrote: >Your honor: on 9/6/00 10:43 PM, David Ross at d_ross@bellsouth.net >confessed: > >> Most of the large and / or broad band ISP. Bellsouth, AOL, etc... use >> caching servers to intercept all port 80 traffic and try and serve it >> locally. To do this they also have to play games with the DNS requests. >> I'm on Bellsouth and when they have problems, yes, surfing gets plain weird. >> >Yes, but... > >It seems to have started last week and I noticed it at home on @home. But >then it happened at our NOC on our T1 which is straight to savvis. >Then it happened at a school I administer on a frac. t1 to Verio. > >I have been having big problems with Akamai sites (ie everybody) for a >while, where images are not completely loading in netscape. But this is >different, this is like the site doesn't even exist til I hit reload. And >it's happened on PC's as well as my Macs, so now I'm wondering if I'm just >crazy :) Sounds like a DNS timeout issue. A typical TCP/IP stack will only wait about 7.5 seconds for the resolver to return a result. But the delay may be longer, since the resolver has to contact several other servers, with a potential for up to 15 seconds of delay before some other server responds. The net result is, your client machine's OS gives up before the local resolver finds the answer, but the answer, when it is discovered (often shortly thereafter), is cached. Thus, on reload, the answer comes back immediately. The solution is one of optimization - make sure you have enough available bandwidth, make sure the DNS server machine is fast enough for whatever programs it's running, etc. Keep in mind that, for Windows and Mac OS, the only resolver that matters is the one listed first in the TCP/IP settings. The others aren't used unless and until the first fails to return quickly enough. ____________________________________________________________________ Chris Buxton Men & Mice cbuxton@menandmice.com We Make DNS Easy!

Messages In This Thread: DNS - site not visible everywhere by Rick Osgood on Sep 6, 2000 at 11:15:51 am Re: DNS - site not visible everywhere by Mark@pageworks.co.uk (Mark Palmer, Pageworks) on Sep 6, 2000 at 11:39:43 am Re: DNS - site not visible everywhere by Aaron Lynch on Sep 6, 2000 at 11:56:19 am Re: DNS - site not visible everywhere by David Ross on Sep 6, 2000 at 10:41:20 pm Re: DNS - site not visible everywhere by Aaron Lynch on Sep 7, 2000 at 1:18:09 am Re: DNS - site not visible everywhere by Men & Mice Support on Sep 7, 2000 at 1:27:36 am Re: DNS - site not visible everywhere by Men & Mice Support on Sep 7, 2000 at 9:40:11 am Re: DNS - site not visible everywhere by Rick Osgood on Sep 7, 2000 at 9:53:31 am Re: DNS - site not visible everywhere by Global Homes Webmaster on Sep 7, 2000 at 9:59:43 am Re: DNS - site not visible everywhere by Rick Osgood on Sep 7, 2000 at 10:15:19 am Re: DNS - site not visible everywhere by Men & Mice Support on Sep 7, 2000 at 10:25:14 am Re: DNS - site not visible everywhere by David Ross on Sep 8, 2000 at 12:19:19 am Re: DNS - site not visible everywhere by Rick Osgood on Sep 8, 2000 at 11:08:46 am Re: DNS - site not visible everywhere by Men & Mice Support on Sep 8, 2000 at 11:29:27 am