Re: IPv6 recap
Sam Varshavchik <[email protected]>
| Newsgroups | gmane.mail.imap.courier.general |
|---|---|
| Message-ID | <[email protected]> |
Alessandro Vesely writes: > It happened again. Yesterday I sent 19 messages to Comcast, 18 were > successfully delivered, one failed after trying to use IPv6. I'd guess > Comcast's server answers after about 4.9 secs, so that when the first query > randomly fails Courier tries the second address. > > I tried to look back at the rfc1035 code to recall how it works. It seems > that if A and AAAA are queried simultaneously, the query fails unless a > response is received for both. In that case, the choice between IPv4 and > IPv6 would be deterministic, wouldn't it? Should I try a patch? The call to rfc1035_mxlist_create_x from do_esmtp_connect_to passes in the RFC1035_MX_IGNORESOFTERR flag. A failure in rfc1035_resolve_cname() is deemed RFC1035_MX_SOFTERR; but if at least one A or AAAA record was included in the MX response, or if at least one additional A or AAAA lookup succeeded, then the lookup is deemed successful, so it should be doing this already. The "after trying to use IPv6" is a red herring. You're seeing this because the IPv6 address was simply the last one that was tried. All A and AAAA addresses were tried, and they were offline. _______________________________________________ courier-users mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
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