> -----Original Message----- > From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On > Behalf Of Paul Heinlein > Sent: Friday, May 23, 2008 2:35 PM > To: CentOS mailing list > Subject: RE: [CentOS] how to debug ssh slow connection issues. > > On Fri, 23 May 2008, Jason Pyeron wrote: > > >>> debug3: Normalising mapped IPv4 in IPv6 address > >>> debug3: Trying to reverse map address 192.168.1.80. > >>> > >>> paused 7 seconds > >> > >> Here, obviously, is part of the problem. Your name service isn't > >> answering reverse lookups for your LAN addresses -- or it least it > >> isn't answering them in a timely manner. Fixing that, either > >> through DNS or /etc/hosts, will help a bunch. > > > > [root at 192.168.1.21 ~]# date && host 192.168.1.80 && date && host > > host80.1.internal.pdinc.us && date Fri May 23 13:55:52 EDT 2008 > > 188.8.131.52.in-addr.arpa domain name pointer host80.1.internal.pdinc.us. > > Fri May 23 13:55:52 EDT 2008 > > host80.1.internal.pdinc.us has address 192.168.1.80 Fri May 23 13:55:52 > EDT > > 2008 > > [root at 192.168.1.21 ~]# > > > > Hmmm, does not take 7 seconds. > > User-space utilities like /usr/bin/host don't always provide an > accurate reflection of the name services inherited by init- or > kernel-launched processes -- especially if the network wasn't (for > reasons unknown) fully functional at boot time. Reboot? > > Do you remember if there were any network timeouts when you booted the > machine in question? Oddly, yes there was. > > Are you running nscd? > [root at devserver21 ~]# chkconfig --list | grep nscd nscd 0:off 1:off 2:off 3:off 4:off 5:off 6:off > I'm still inclined to believe that hostname-lookup issues are involved > here; an strace with timestamps might provide a better glimpse of the > exact system calls that are timing out. Like wise, but with local DNS and local IPs humming perfectly? -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- - - - Jason Pyeron PD Inc. http://www.pdinc.us - - Principal Consultant 10 West 24th Street #100 - - +1 (443) 269-1555 x333 Baltimore, Maryland 21218 - - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. If you have received it in error, purge the message from your system and notify the sender immediately. Any other use of the email by you is prohibited.