[BUG] 2.5.65 ipv6 TCP checksum errors (capture attached)

[bert hubert]

This is a MIME-formatted message.  If you see this text it means that your
E-mail software does not support MIME-formatted messages.

--=_courier-30970-1048078044-0001-2
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Interestingly, the initial ssh connection worked, the second one failed.
Subsequent attempts fail too.

This all over ipv6:

hubert# tcpdump -r file -v -v
29.09 snapcount.33408 > hubert.ssh: S [tcp sum ok] 2737328594:2737328594(0) win 5760 <mss 1440,sackOK,timestamp 10690463 0,nop,wscale 0> (len 40, hlim 64)
29.09 hubert.ssh > snapcount.33408: S [tcp sum ok] 2399386333:2399386333(0) ack 2737328595 win 5712 <mss 1440,sackOK,timestamp 10865690 10690463,nop,wscale 0> (len 40, hlim 64)
29.09 snapcount.33408 > hubert.ssh: . [tcp sum ok] 1:1(0) ack 1 win 5760 <nop,nop,timestamp 10690464 10865690> (len 32, hlim 64)
29.10 hubert.ssh > snapcount.33408: P [bad tcp cksum 4f2!] 1:41(40) ack 1 win 5712 <nop,nop,timestamp 10865695 10690464> (len 72, hlim 64)
29.30 hubert.ssh > snapcount.33408: P [bad tcp cksum 3bf1!] 1:41(40) ack 1 win 5712 <nop,nop,timestamp 10865896 10690464> (len 72, hlim 64)
29.83 hubert.ssh > snapcount.33408: P [bad tcp cksum 23ef!] 1:41(40) ack 1 win 5712 <nop,nop,timestamp 10866432 10690464> (len 72, hlim 64)
30.86 hubert.ssh > snapcount.33408: P [bad tcp cksum 23eb!] 1:41(40) ack 1 win 5712 <nop,nop,timestamp 10867456 10690464> (len 72, hlim 64)

Both hosts run 2.5.65. hubert.ipv6.ds9a.nl (publically routable, so you
can try to ssh to me as long as I'm not asleep, the machine is next to my
bed) is a pentium pro 200. Kernel was make mrpropered before compiling,
virgin kernel.

Capture attached.

Regards,

bert

-- 
http://www.PowerDNS.com      Open source, database driven DNS Software 
http://lartc.org           Linux Advanced Routing & Traffic Control HOWTO
http://netherlabs.nl                         Consulting
--=_courier-30970-1048078044-0001-2
Content-Type: application/octet-stream
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=bad-csum
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--=_courier-30970-1048078044-0001-2--