Description of problem: postfix has a configuration option to turn on ipv6 support. with the push for supporting ipv6 this should be enabled by default from http://www.postfix.org/IPV6_README.html /etc/postfix/main.cf: # You must stop/start Postfix after changing this parameter. inet_protocols = ipv4 (DEFAULT: enable IPv4 only) inet_protocols = all (enable IPv4, and IPv6 if supported) inet_protocols = ipv4, ipv6 (enable both IPv4 and IPv6) inet_protocols = ipv6 (enable IPv6 only) we currently don't have this in the config it should be inet_protocols = all that way things wont break if the end user disables ipv6 support on their system Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info:
ping Please fix this
The problem with enabling IPv6 is that postfix will try to deliver emails over IPv6 before trying over IPv4. In consequence this would be a noticeable slowdown in mail delivery for most current systems, which are using IPv4 only. Please enable IPv6 if you need it for your system with "postconf -e inet_protocols=all" and restart postfix afterwards. I am sorry, but I have to defer this for now.
It shouldn't cause a noticeable slowdown at all. RFC3484 essentially says that unless you have a global IPv6 address, you shouldn't be trying to connect to a remote server by IPv6. And even if you do, the kernel will return failure immediately if you have no route. Please fix this bug.
IPv6 enabled in rawhide in package postfix-2.4.6-1.fc9.