On 9/11/07, Jun Salen <nokijun@xxxxxxxxx> wrote: > >Hi List, > > > >My Mail/Proxy server has from time to time refuse to > >accept accept network connection. If I restart the > >network service, the service will again start to > >accept connection but after some time will again > >refuse connection. I use CentOS 4.5 with Squid, > >DansGuardian, Postfix. Please can someone point me > >what are the possible cause of this. Thank you. > > In addition to my posting above. When I make ping to > other machine from the server, the server will again > restore and accept connection. This is weird, so my > temporary solution is to let the server continually > ping other machine. Please help. Thanks again. > Ping is a very cheap and acceptable solution ! Anyway you'r certainly curious about the problem :-) This is a problem about ARP request. Maybe another machine with low activity share the same IP or your swith/hub is badly configured ! You can use arping to detect any device with the same IP and tcpdump to look for arp request."arp -an" will show you the arp table. Regards > junji > aisalen.wordpress.com > Linux Registered User #253162 > > Send instant messages to your online friends http://uk.messenger.yahoo.com > _______________________________________________ > CentOS mailing list > CentOS@xxxxxxxxxx > http://lists.centos.org/mailman/listinfo/centos > -- Alain Spineux aspineux gmail com ----------------------- When I do /sbin/arp -an in the server box it does not contain entries for ip address where the server, it is ok? I observed that when I ping the server from other machine, it replies but from time to time displays time-out. We use this server for our mail and proxy so it is affecting us when time outs occur. Tsk tsk. junji aisalen.wordpress.com Linux Registered User #253162 Send instant messages to your online friends http://uk.messenger.yahoo.com _______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos