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corrupt arp tables?<BR>
bad physical hardware?<BR> <BR>> Date: Fri, 5 Jun 2009 21:01:43 -0400<BR>> From: jsellens-Iv5KO+h6AVB+Y12zHexnB0EOCMrvLtNR@public.gmane.org<BR>> To: tlug@ss.org<BR>> Subject: Re: [TLUG]: Troubleshooting erratic network performance<BR>> <BR>> Oh oh - someone broke rule number one on you: no changes Friday<BR>> afternoon.<BR>> <BR>> Could there be a DNS resolution problem? Could apache be trying<BR>> to do a reverse lookup on the IP address connecting and be timing<BR>> out? Do the apache access logs show IP addresses or hostnames?<BR>> Can each DNS server in /etc/resolv.conf be reached and succeed<BR>> in doing a forward and reverse lookup? e.g.<BR>> dig @1.2.3.4 asbestos.ss.org<BR>> dig @1.2.3.4 1.5.108.206.in-addr.arpa. ptr<BR>> <BR>> Does the web page connect to a backend server e.g. mysql?<BR>> I had a slow page problem just the other week, because the<BR>> mysql server couldn't do reverse lookups on the IP of the<BR>> web server, which could be resolved either by fixing DNS<BR>> or adding an appropriate local entry to /etc/hosts.<BR>> <BR>> You could watch DNS traffic and expect to see answers and<BR>> quick replies with tcpdump, if you know what interface to<BR>> watch.<BR>> <BR>> Any idea what changed?<BR>> <BR>> Hope that helps!<BR>> <BR>> John<BR>> --<BR>> The Toronto Linux Users Group. Meetings: http://gtalug.org/<BR>> TLUG requests: Linux topics, No HTML, wrap text below 80 columns<BR>> How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists<BR><br /><hr />Internet Explorer 8 makes surfing easier. <a href='http://go.microsoft.com/?linkid=9655264' target='_new'>Get it now! </a></body>
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