On Wed, 4 Jan 2012, Jan Engelhardt wrote: > On Wednesday 2012-01-04 10:03, Jozsef Kadlecsik wrote: > > >On Wed, 4 Jan 2012, Hans Schillstrom wrote: > > > >> On Wednesday 04 January 2012 09:28:05 Jozsef Kadlecsik wrote: > >> > > >> > On Wed, 4 Jan 2012, Hans Schillstrom wrote: > >> > > >> > > In some cases it not desirable to have auto defrag. > >> > > Ex. in a cluster where packets can arrive on different blades. > >> > > In that case it is possible to use containers (LXC) and send > >> > > all fragments to one place where defrag is enabled. > >> > > > >> > > This patch makes it possible to turn off the defrag per network name space, > >> > > by setting net.netfilter.nf_conntrack_nodefrag to 1. > >> > > Both IPv4 and IPv6 is effected by this sysctl. > >> > > Default is 0 which is defrag. > >> > > >> > Conntrack assumes that the packets are defragmented and will drop any > >> > unfragmented one. So your patch results packet drops. > >> > >> Hmmm, more work... > >> > > >> > Also, if you want to disable defragmentation then why don't you simply > >> > "mark" the packets with the NOTRACK target? > >> > >> I don't think that will work since NF_IP_PRI_CONNTRACK_DEFRAG is -400 > > > >Then change NF_IP_PRI_RAW so that it precedes NF_IP_PRI_CONNTRACK_DEFRAG. > >The raw table should be made possible to completely override conntack and > >defrag is implicit part of the latter. > > We've been there (me in the thread even) - defrag is running before raw, > because otherwise you could not select packets based upon L4 > parameters for non-defrag in the first place: > > -t raw ... -p udp --dport 53 -j CT --notrack > > Not that I overly care about whether defrag is before/after raw.. You mean "for non-conntrack", but you are right. Nice cicle :-). So we can sum up that either the system has got conntrack enabled which requires defrag, or there's no defrag but then there's no conntrack at all. Best regards, Jozsef - E-mail : kadlec@xxxxxxxxxxxxxxxxx, kadlecsik.jozsef@xxxxxxxxxxxxx PGP key : http://www.kfki.hu/~kadlec/pgp_public_key.txt Address : Wigner Research Centre for Physics, Hungarian Academy of Sciences H-1525 Budapest 114, POB. 49, Hungary -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
