Bernhard Bock wrote: > Pablo Neira Ayuso wrote: >> That's exactly the test that I do in my testbed and it works fine here, >> the problem must be elsewhere. The following line should help to see how >> the connection tracking is marking the traffic as invalid: >> >> echo 255 > /proc/sys/net/ipv4/netfilter/ip_conntrack_log_invalid >> >> However, please see the comment below before doing this and repeating >> the test. > > I didn't know one can increase the verbosity. Now I get some (more) > helpful logs. > > kernel: nf_ct_tcp: invalid packet ignored IN= OUT= SRC=10.5.0.101 > DST=10.6.6.102 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=9977 DF PROTO=TCP > SPT=39101 DPT=80 SEQ=3381624888 ACK=0 WINDOW=5840 RES=0x00 SYN URGP=0 OPT > > Invalid syn packet? Hm. And then: > > kernel: nf_ct_tcp: killing out of sync session IN= OUT= SRC=10.6.6.102 > DST=10.5.0.101 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=0 DF PROTO=TCP SPT=80 > DPT=41647 SEQ=3243074286 ACK=3280173284 WINDOW=5792 RES=0x00 ACK SYN > URGP=0 OPT I though that your problem was that you cannot even recover the flows in the first failover, but it seems to me that you have triggered several fail-overs between the nodes. There's no way to hit this in a clean session - ie. empty connection tracking table. Please, see the end of this email. >> Are you using a sane stateful rule-set similar to the described in the >> conntrack-tools website? What kernel version are you using? If your >> kernel is < 2.6.22 you have to disabled TCP window tracking on both nodes. >> >> echo 1 > /proc/sys/net/ipv4/netfilter/ip_conntrack_tcp_be_liberal > > > I'm using 2.6.25, from Fedora 9. > And I have set /proc/sys/net/netfilter/nf_conntrack_tcp_be_liberal to 1. > > Here are my rules: > > -A FORWARD -m state --state INVALID -j LOG --log-prefix "Invalid:" > -A FORWARD -m state --state INVALID -j DROP > -A FORWARD -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "New > not syn:" > -A FORWARD -p tcp ! --syn -m state --state NEW -j DROP > -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT > -A FORWARD -m state --state NEW -m tcp -p tcp --syn -d 10.6.6.0/24 -j ACCEPT > -A FORWARD -m state --state NEW -m udp -p udp -s 10.5.0.0/24 -d > 10.6.6.0/24 -j ACCEPT > -A FORWARD -j LOG --log-prefix "Packet dropped:" > -A FORWARD -j DROP Looks sane. >> There is a new script `primary-backup.sh' that replaces the old >> script_master.sh and script_backup.sh. Although this is not directly >> related it would be worth to use that instead as it will be the standard >> in the upcoming release. > > I'll replace it for future tests. For now, I don't want to mess around > at too many places at the same time unless it's related to the problem. If you are triggering several fail-overs with unclean session, the new script should help. So please, give it a try. It will take you a couple of minutes to get it working. -- "Los honestos son inadaptados sociales" -- Les Luthiers -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
