Hello Eric, Of course, the best solution here is to disable IPv6 on system level. Just thought probably it was a specific option in opensmtpd which could regulate it.
--- wbr, Denis. On Fri, Jun 21, 2013 at 12:39 PM, Eric Faurot <[email protected]> wrote: > On Fri, Jun 21, 2013 at 04:48:22AM +0600, Denis Fateyev wrote: > > > > Hello there, > > Is there an option to select MX type order for outgoing messages (IPv4 > > first, then IPv6, or vice versa), and/or entirely disable IPvX usage > > for outgoing sessions? > > For example, I have a bunch of machines that don't have IPv6 support, > > so while sending mails to @[1]gmail.com 'smtp-out' always starts from > > IPv6 MX which produces only faulty connection attempts and wastes > time. > > I haven't found an option in program to force IPv4 using. > > More general: is there an option in global scope which controls > allowed > > protocols? > > I can think of two ways to do that at the moment. > > One way is to add "family inet4" to your resolv.conf. I think it is > only officially supported on OpenBSD, but smtpd will handle it fine, > whatever system you run. A drawback is that it is a global setting, > but if you don't have ipv6 on those machines it should be fine. Of > course, the biggest problem is that you need a resolver option that > might not be available on your system, which is maybe not desirable, > from an admin point of view. > > An other way is to add an explicit source address (or table) on your > relay rules: "accept for any relay source aaa.bbb.ccc.ddd". This way > smtpd will only attempt to connect to host on their v4 address. The > problem is that you have to hard-code your IP in the config file. It > might be acceptable though, at least as a temporary workaround. > > I would say use the first option on OpenBSD. Otherwise either ignore > the failures, or use the second option for now. > > Eric. >
