[outages] odd gmail issue.. inet6 ?

[Mike Tancsa]

I noticed on a couple of our mail servers, delivery to gmail was getting
stuck in the outbound queue.  Our MTAs are all sendmail

If I hardcode delivery to gmail to 74.125.142.26 via a mailertable
entry, mail goes through fine

But if let it naturally select the inet6 addr, it hangs


Running /var/spool/mqueue/rBLDcRmZ092661 (sequence 1 of 1)
<miketancsa at gmail.com>... Connecting to gmail-smtp-in.l.google.com. via
esmtp...
220 mx.google.com ESMTP v3si9282987qat.181 - gsmtp
>>> EHLO smarthost2.sentex.ca
250-mx.google.com at your service, [2607:f3e0:80:80::2]
250-SIZE 35882577
250-8BITMIME
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-PIPELINING
250 CHUNKING
>>> STARTTLS
220 2.0.0 Ready to start TLS


The addr is of course reachable. I check the routing and the AS seems
legit. The path is 6939 15169

traceroute6 to 2607:f8b0:400d:c02::1a (2607:f8b0:400d:c02::1a) from
2607:f3e0:80:80::2, 64 hops max, 12 byte packets
 1  2607:f3e0:80:80::1  0.585 ms
 2  toronto-torix-6  0.478 ms
 3  gw-he.ip6.torontointernetxchange.net  0.995 ms
 4  2001:478:245:1::6  1.104 ms
 5  2001:4860::1:0:28  1.684 ms
 6  2001:4860::8:0:4398  15.514 ms
 7  2001:4860::8:0:6375  21.308 ms
 8  2001:4860::8:0:5e9d  37.368 ms
 9  2001:4860::2:0:3568  28.932 ms
10  *
11  *
12  *
13  qe-in-x1a.1e100.net  28.663 ms


I am coming from 2607:f3e0:80:80::2 in the above case

tcpdump doesnt show anything obvious and since the payload is not
readble I cant see it.  I wonder if there is a way to get sendmail to
print out the contents...

-- 
-------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada   http://www.tancsa.com/