NFS over IPv6

With today's kernel, I see strange behavior with NFS over IPv6.  My
userland is two days older.  I'll check with sync'ed kernel/userland
tomorrow.

# NFS server is 5.2.1R, client is current.

When I did some write operation, it may wait too long.  I can
sometimes write without problem, but sometimes not.  I took tcpdump -vvv:

22:48:25.128338 2001:218:422:2::XXXX > 2001:218:422:2::YYYY: frag (0xdf59d78f:0|1448) 2001:218:422:2::XXXX.1516376639 > 2001:218:422:2::YYYY.2049: 1440 write fh 1034,59016/16299072 4586 bytes _at_ 0xc000 <unstable> [flowlabel 0x56097] (len 1456, hlim 64)
22:48:25.128371 2001:218:422:2::XXXX > 2001:218:422:2::YYYY: frag (0xdf59d78f:1448|1448) [flowlabel 0x56097] (len 1456, hlim 64)
22:48:25.128405 2001:218:422:2::XXXX > 2001:218:422:2::YYYY: frag (0xdf59d78f:2896|1448) [flowlabel 0x56097] (len 1456, hlim 64)
22:48:25.128430 2001:218:422:2::XXXX > 2001:218:422:2::YYYY: frag (0xdf59d78f:4344|400) [flowlabel 0x56097] (len 408, hlim 64)
22:48:25.129335 2001:218:422:2::YYYY.2049 > 2001:218:422:2::XXXX.1516376639: reply ok 160 write PRE: sz 0xd1ea mtime 1089294496.000000 ctime 1089294496.000000 POST: REG 664 ids 1000/1000 sz 0xd1ea nlink 1 rdev 199/65077248 fsid 0x420 fileid 0xf8b440 a/m/ctime 1089287695.000000 1089294502.000000 1089294502.000000 4586 bytes <unstable> (len 168, hlim 64)
22:48:25.129489 2001:218:422:2::XXXX > 2001:218:422:2::YYYY: [icmp6 sum ok] icmp6: 2001:218:422:2::XXXX udp port 829 unreachable (len 216, hlim 64)

I don't know why client side replied as port unreachable.  With IPv4,
there is no problem.


-- 
Jun Kuriyama <kuriyama_at_imgsrc.co.jp> // IMG SRC, Inc.
             <kuriyama_at_FreeBSD.org> // FreeBSD Project