[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: iptables MARK breaks radvd



Pascal Hambourg wrote at 2010-07-01 06:57 -0500:
> green a écrit :
> > Debian Squeeze is running on a Soekris net5501 as an internet gateway.
> > 
> > For use with shaping, there is an ip6tables rule like this:
> >  ip6tables -t mangle -A OUTPUT -j MARK --set-mark 0x4/0xf
> > And the same with iptables (ipv4).
> > 
> > radvd is set up to provide ipv6 addresses to LAN clients.
> > 
> > Unfortunately the above ip6tables rule breaks radvd.  Nothing different happens 
> > except clients do not seem to see the advertisements and so get no ipv6 
> > address.
> 
> Can you do packet captures on all relevant interfaces/ports and check
> whether the router advertisements are actually sent and received ?
> 
> (Regardless of this issue, I would exclude neighbour discovery packets
> from any shaping.)

(First, I disabled shaping altogether.)
Listening with wireshark at a client system.

Rule in place:
1. radvd running
2. client connects
3. client sends solicitation to ff02::2
4. no response
5. no advertisements
6. manual rdisc6 solicitations time out (with ipv6 address set manually)

No MARK rule:
1. radvd running
2. client connects
3. client sends solicitation to ff02::2
4. server responds with advertisement
5. advertisements continue
6. manual rdisc6 solicitations are successful

An advertisement packet:
459	283.294265	fe80::200:24ff:fecc:5cb5	ff02::1	ICMPv6	Router advertisement
0000   00 02 00 01 00 06 00 00 24 cc 5c b5 00 00 86 dd  ........$.\.....
0010   60 00 00 00 00 38 3a ff fe 80 00 00 00 00 00 00  `....8:.........
0020   02 00 24 ff fe cc 5c b5 ff 02 00 00 00 00 00 00  ..$...\.........
0030   00 00 00 00 00 00 00 01 86 00 83 3f 40 00 00 3c  ...........?@..<
0040   00 00 00 00 00 00 00 00 03 04 40 c0 00 01 51 80  ..........@...Q.
0050   00 00 38 40 00 00 00 00 20 01 04 70 c1 91 00 00  ..8@.... ..p....
0060   00 00 00 00 00 00 00 00 01 01 00 00 24 cc 5c b5  ............$.\.

Shall I run something to capture at the server?  Would you like to see some 
other packets?  Shall I use something other than wireshark?

Thanks.

Attachment: signature.asc
Description: Digital signature


Reply to: