On 23.01.2011 13:21, Mario 'BitKoenig' Holbe wrote: > Hello, > > I have a strange issue with netfilter MARK on IPv6 which I cannot > explain and which I believe to be a kernel bug: > If I mark outgoing IPv6 packets they appear to be transmitted via the > wrong physical interface. At least multicast packets - at least some of > them. > > I'm running a Linux-based router with two local interfaces and radvd > advertises stateless autoconfiguration information on them. > If I mark all outgoing IPv6 packets, after some time all hosts on both > subnets appear to be autoconfigured for both subnets, i.e. they all have > two IPv6 addresses - one of each subnet and two default routes - one for > each router interface. Of course, only one of them really works on each > host. > > The gateway does pretty normal routing, no routing policies, > particularly no fwmark rules, does no bridging or something like that. > The network interfaces are Intel driven by e100. > > The following debug session is done with a 2.6.32 kernel, the condensed > packet information originates from tcpdump: > > Without marking everything runs as it should be. > Marking eth0 packets results in all advertisements transmitted via eth1. > The behaviour goes back to normal as soon as the marking disappears. > Marking eth1 packets doesn't appear to change the normal behaviour at > the first glance, but with that I experience hiccups after some time of > inactivity (i.e. from time to time ping6 from one subnet to the other > gets no answers for the first 6 to 8 packets). > > I also tried marking with 0xff00 instead of 1 - same results. > I tested this on kernels 2.6.26, 2.6.32, and 2.6.37 - all show the same > behaviour. That probably means that we're not using the correct keys when rerouting in ip6_route_me_harder(). Just for testing, please try to disable the ip6_route_me_harder() call in net/ipv6/netfilter/ip6table_mangle.c::ip6t_mangle_out(). -- 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
