On Sun, Apr 10, 2011 at 3:28 AM, Matthew Dempsky <matt...@dempsky.org> wrote:
> There have been some changes to how checksums are handled in the
> kernel (in particular with bridges), so I can believe this was
> affected.
>
> Try running "tcpdump -s 65535 -v udp port bootps or udp port bootpc"
> on various interfaces on both the server and the clients. It should
> warn if it sees bad checksums, and can help track down what's going
> on.
On the clients, checksums are ok.
On the server, checksums are ok on the bridge and physical interfaces
(vr0 and vr1) but not on vether interfaces:
$ sudo tcpdump -i vr0 -s 65535 -v udp port bootps or udp port bootpc
<
tcpdump: listening on vr0, link-type EN10MB
^C
79 packets received by filter
0 packets dropped by kernel
$ sudo tcpdump -i vr1 -s 65535 -v udp port bootps or udp port bootpc
tcpdump: listening on vr1, link-type EN10MB
03:33:11.937955 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0xe23d6fe3 vend-rfc1048 HN:"freekc" RQ:freekc.panam.brimbelle.org
DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos 0x10] (ttl 16, id 0, len 328)
03:33:12.942426 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0xe23d6fe3 secs:1 vend-rfc1048 HN:"freekc"
RQ:freekc.panam.brimbelle.org DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos
0x10] (ttl 16, id 0, len 328)
^C
5 packets received by filter
0 packets dropped by kernel
$ sudo tcpdump -i vether0 -s 65535 -v udp port bootps or udp port bootpc
tcpdump: listening on vether0, link-type EN10MB
03:34:05.109195 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0x67aba28a vend-rfc1048 HN:"freekc" RQ:freekc.panam.brimbelle.org
DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos 0x10] (ttl 16, id 0, len 328,
bad cksum 0!)
03:34:06.114124 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0x67aba28a secs:1 vend-rfc1048 HN:"freekc"
RQ:freekc.panam.brimbelle.org DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos
0x10] (ttl 16, id 0, len 328, bad cksum 0!)
^C
66 packets received by filter
0 packets dropped by kernel
$ sudo tcpdump -i vether1 -s 65535 -v udp port bootps or udp port bootpc
tcpdump: listening on vether1, link-type EN10MB
03:34:28.549541 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0x76f52a27 vend-rfc1048 HN:"freekc" RQ:freekc.panam.brimbelle.org
DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos 0x10] (ttl 16, id 0, len 328,
bad cksum 0!)
03:34:29.554754 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0x76f52a27 secs:1 vend-rfc1048 HN:"freekc"
RQ:freekc.panam.brimbelle.org DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos
0x10] (ttl 16, id 0, len 328, bad cksum 0!)
^C
3 packets received by filter
0 packets dropped by kernel
$ sudo tcpdump -i bridge0 -s 65535 -v udp port bootps or udp port bootpc
tcpdump: listening on bridge0, link-type EN10MB
03:34:48.173526 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0x604fe8b3 vend-rfc1048 HN:"freekc" RQ:freekc.panam.brimbelle.org
DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos 0x10] (ttl 16, id 0, len 328)
03:34:49.185256 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok]
xid:0x604fe8b3 secs:1 vend-rfc1048 HN:"freekc"
RQ:freekc.panam.brimbelle.org DHCP:DISCOVER PR:SM+BR+DG+DN+NS+HN [tos
0x10] (ttl 16, id 0, len 328)
^C
146 packets received by filter
0 packets dropped by kernel
--
Mattieu Baptiste
"/earth is 102% full ... please delete anyone you can."
