[nsd-users] nsd: Could not tcp connect to a:a:a:a::1:1: Operation timed out

Willem Toorop willem at nlnetlabs.nl
Thu Dec 27 10:03:53 CET 2012


Hi Michael,

Your configuration looks good.

Op 26-12-12 16:23, Michael Grimm schreef:
> Both servers are running well, serving all requests as expected, and the master is delivering all zones with afxr at startup perfectly well. But, I get the following error messages (for IPv6 address, only!) in the *slave*'s syslog:
> | nsd: Could not tcp connect to a:a:a:a::1:1: Operation timed out
> 
> tcpdump at the *master* tells me (shortend to the relevant part):
> | pass in on em0: (flowlabel 0x360ed, hlim 63, next-header TCP (6) payload length: 40) b:b:b:b::1:1.15298 > a:a:a:a::1:1.53: Flags [S], cksum 0xfedd (incorrect -> 0x7df6), seq 1459122906, win 65535, options [mss 1440,nop,wscale 6,sackOK,TS val 333780857 ecr 0], length 0

I suspect the master and the slave are on the same host causing the
checksum error (because checksum calculation is offloaded to the NIC).
Is this true?

Is this the only packet you saw for the handshake? Did you see an
Syn/Ack after this packet? I.e. A packet returning from a:a:a:a::1:1
with "Flags [S.]"?

Do you see the tcp6 listening socket on the master with "sockstat -l"?

Do you use carp devices for the jails. I have seen some weird ipv6
routing behaviour with those myself.

Regards,

-- Willem


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