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<DIV>Try running strace against the DHCP pid and see if it is trying to access a resource that is not available or is running slow, like DNS.</DIV>
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<DIV><BR><BR>>>> "Kelvin Williams" <kelvin-lists@williamschadwell.com> 12/15/2008 8:47 AM >>><BR>I just executed a sniff on the DHCP Server. This is for ONE client. <BR><BR>TimeMessageTransaction ID<BR>21sDISCOVER0x1179<BR>25sOFFER0x1179<BR>26sDISCOVER0x117a<BR>34sOFFER0x117a<BR>35sDISCOVER0x117b<BR>44sOFFER0x117b<BR>46sREQUEST0x117b<BR>50sREQUEST0x117b<BR>54sACK0x117b<BR>58sACK0x117b<BR><BR>The client is getting all messages; but appears to be giving up and starting<BR>again after the wait.<BR><BR>kw<BR><BR>-----Original Message-----<BR>From: dhcp-users-bounces@lists.isc.org<BR>[mailto:dhcp-users-bounces@lists.isc.org] On Behalf Of Tom Greaser<BR>Sent: Monday, December 15, 2008 10:10 AM<BR>To: 'Users of ISC DHCP'<BR>Subject: RE: Sudden Slow Performance<BR><BR>Have you sniffed / snooped a station to see if its getting this Offer / ACK<BR>?<BR><BR><BR><BR><BR>>>> "Kelvin Williams" <kelvin-lists@williamschadwell.com> 12/15/08 9:52 AM<BR>>>> <BR>The entire network. <BR><BR>-----Original Message-----<BR>From: dhcp-users-bounces@lists.isc.org<BR>[mailto:dhcp-users-bounces@lists.isc.org] On Behalf Of Tom Greaser<BR>Sent: Monday, December 15, 2008 9:47 AM<BR>To: 'Users of ISC DHCP'<BR>Subject: RE: Sudden Slow Performance<BR><BR>Is this effecting All of your network or just a few subnets ?<BR><BR>Ive had issues like this.. but only for specific networks.. I had a switch<BR>that<BR>would auto prune spanning tree .. Thus i would get the DHCPDISCOVER but<BR>never the clients would never see the <BR>DHCPOFFER. <BR><BR>I manually made sure that network was never pruned.. <BR><BR><BR><BR><BR><BR>>>> "Kelvin Williams" <kelvin-lists@williamschadwell.com> 12/15/08 9:38 AM<BR>>>> <BR>Network good. No errors on the interfaces.<BR><BR>No disk errors reported.<BR><BR>No patches applied.<BR><BR>CPU and Memory levels are good.<BR><BR>Number of clients always increases--but not a drastic amount. Maybe 50 new<BR>clients.<BR><BR><BR><BR>-----Original Message-----<BR>From: dhcp-users-bounces@lists.isc.org<BR>[mailto:dhcp-users-bounces@lists.isc.org] On Behalf Of Glenn Satchell<BR>Sent: Monday, December 15, 2008 9:25 AM<BR>To: dhcp-users@lists.isc.org<BR>Subject: Re: Sudden Slow Performance<BR><BR><BR>>From: "Kelvin Williams" <kelvin-lists@williamschadwell.com><BR>>To: <dhcp-users@lists.isc.org><BR>>Subject: Sudden Slow Performance<BR>>Date: Mon, 15 Dec 2008 08:57:08 -0500<BR>>X-Spam-Level: ***<BR>>X-BeenThere: dhcp-users@lists.isc.org<BR>><BR>> We've been operating one of our DHCP Servers for approximately 6 months<BR>> without any issues. This server is on a network with about 2,500 hosts.<BR>> The server has worked flawlessly until last week when it became extremely<BR>> slow. <BR>> <BR>> Clients are having to send multiple DISCOVERs before the server will<BR>> respond, and sometimes the server does not respond timely to a REQUEST.<BR>> Causing the clients to timeout and stop attempting.<BR>> <BR>> We've reviewed the server's load, and its very, very light. vmstat<BR>doesn't<BR>> show any bottlenecks in the processor or disk. The current version we are<BR>> running is 3.1.1; <BR>> <BR>> As I stated, this all occurred within the last week. Can anyone recommend<BR>> something to check? Or is there a way to get greater verbosity from the<BR>> debug mode?<BR>> <BR>> Many thanks in advance.<BR>> <BR>> Kw<BR><BR>Have you checked out the hardware, network, etc? Maybe there is a hardware <BR>fault. Consider the slow dhcp response to be a symtim rather than the fault?<BR><BR>Could be a number of things:<BR><BR>- faulty network. try a different cable and/or switch port and/or nic<BR><BR>- disk errors. check logs for warnings or errors<BR><BR>- operating system patches. done any os patches around the time it went bad?<BR><BR>- any other system changes at that time?<BR><BR>- rogue process using all available cpu or memory?<BR><BR>- did the number of clients increase that week?<BR><BR>regards,<BR>-glenn<BR><BR>_______________________________________________<BR>dhcp-users mailing list<BR>dhcp-users@lists.isc.org<BR><A href="https://lists.isc.org/mailman/listinfo/dhcp">https://lists.isc.org/mailman/listinfo/dhcp</A>-users<BR><BR>_______________________________________________<BR>dhcp-users mailing list<BR>dhcp-users@lists.isc.org<BR><A href="https://lists.isc.org/mailman/listinfo/dhcp">https://lists.isc.org/mailman/listinfo/dhcp</A>-users<BR><BR>_______________________________________________<BR>dhcp-users mailing list<BR>dhcp-users@lists.isc.org<BR><A href="https://lists.isc.org/mailman/listinfo/dhcp">https://lists.isc.org/mailman/listinfo/dhcp</A>-users<BR><BR>_______________________________________________<BR>dhcp-users mailing list<BR>dhcp-users@lists.isc.org<BR><A href="https://lists.isc.org/mailman/listinfo/dhcp">https://lists.isc.org/mailman/listinfo/dhcp</A>-users<BR><BR>_______________________________________________<BR>dhcp-users mailing list<BR>dhcp-users@lists.isc.org<BR><A href="https://lists.isc.org/mailman/listinfo/dhcp">https://lists.isc.org/mailman/listinfo/dhcp</A>-users<BR><BR>_______________________________________________<BR>dhcp-users mailing list<BR>dhcp-users@lists.isc.org<BR><A href="https://lists.isc.org/mailman/listinfo/dhcp">https://lists.isc.org/mailman/listinfo/dhcp</A>-users<BR></DIV><BR>
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