Wietse Venema: > wishmaster: > > Hi! > > > > I have strange behavior of Postfix (postfix-2.11.1_1,1) > > > > I use FreeBSD as base system and some jails. Each jail use > > virtual network stack (vnet). Problem is in latency when > > connection is outside from the base system only. > > > > telnet localhost 25 works fine, but if this connection or from > > jail or from LAN it is latency about 10 seconds before I see 220 > > example.com.ua ESMTP Postfix
Another cause of delays is having IPv6 and IPv4 address for the destination host, but IPv6 is broken so the client falls back to IPv4 after 10 seconds. I had that yesterday with a non-jail host. > Is that 10 seconds to establish a TCP connection? The telnet client > looks up the destination host address, and your host may be configured > to query DNS before searching /etc/hosts. With a bad /etc/resolv.conf > file, or with bad firewalling/routing for DNS queries/replies, that > causes delays, typically a multiple of 5 seconds (RES_TIMEOUT=5). > > Is that 10 seconds for Postfix to respond after TCP completes? This > is typically the result of a bad /etc/resolv.conf file, but may > also be caused by bad firewalling/routing for DNS queries/replies, > typically causing delays of a multiple of 5 seconds (RES_TIMEOUT=5). > > So the proceduce is: > > 1) Disable chroot in master.cf (all columns 5 = "n") and "postfix > reload". > > 2) Check your /etc/resolv.conf. > > 3) Check your /etc/host.conf and /etc/nsswitch.conf. > > Wietse >
