Hi! I've just seen a rather weird behaviour with smtpd on my box (recently updated to OpenBSD-4.9).
The setup is very simple: All mail gets forwarded using my smarthost. The only "problem": The smarthost in question is also reachable by IPv6, and accordingly has an AAAA record. smtpd sees this, tries to connect using IPv6, but seemingly botches the attempt in a particularily strange way: | startup [debug mode] | [...] | smtp: will accept at most 246 clients | [...] | mta: getting datafd | mta: connect IPv6:2001:1418:153:ffff:: | mta: new status for [email protected]: 110 connect error: Host is down | mta: connect IPv6:2001:1418:153:ffff:: | mta: new status for [email protected]: 110 connect error: Host is down | mta: connect 94.95.177.106 | mta: entering smtp phase | [...] Instead of using the full IPv6 address, it only uses the subnet prefix of the smarthost. This of course fails horribly, leading to a two-minute timeout, and then finally the mail goes through using IPv4 only. The configuration is basic, no surprises here: | listen on lo0 | accept for all relay via mailin.aleturo.com First, I thought it might be a DNS problem, but manual lookups are ok: | mailin.aleturo.com has address 94.95.177.106 | mailin.aleturo.com has IPv6 address 2001:1418:153:ffff:260:8ff:fe0b:35c7 Also, specifying the literal IPv6 address in smtpd.conf doesn't help, and produces the exact same result as above (minus the IPv4 connection at the end). I find it difficult to imagine that this is standard behaviour for smtpd, so I'm assuming that something on my machine might be misconfigured in some obscure way -- but I have no clue to what this might be. Is this a true and genuine bug -- in which case, I can stop worrying and trying to find configuration errors on my part -- or might there be something that I've overlooked? Thanks, Stefan
