Hi, I haven't find any resources about rp_filter and IPv6. Did you simply check that /proc/sys/net/ipv6/conf/all/forwarding was set to 1?
On Mon, Aug 13, 2012 at 9:48 AM, Reinier Boon <[email protected]> wrote: > Hi Igor, > > Thanks for your help and time! > > > First question: does the router A see the response coming from > > router B and then drop it or does the router B drop the packet? > > Router A sees the packets coming in (I see them when I run tcpdump). > > > Second question: why don't you configure router A to go through > > router B as a prefered route to access the internet and use VlanY > > as a fallback in case router B gets down? > > That is what I think is the nature of using BGP: you get asymmetric > routes, where each router uses the shortest path to the internet, and > the return traffic may come via any router. > > > Anayway, as far as I understand your problem, the packet would be > > returned to router A on a different interface from where it was sent. > > That is correct. > > > So the interface of your router A will receive a packet from > > router B but destination IP address is the one of VlanY which > > is not matching the interface getting it and causes the DROP. > > Router A should just route the packet to the correct interface/socket. > It does so for ping6... > > > You can probably setup an NDP proxy to solve this but it is an > > ugly solution . > > NDP may be necessary when router B does not know where to send a package > (which you can detect by seeing the Neighbour Sollicitation packets). > But router B knows where to send the packages: router A and B share > routes via OSPF, and I see the packages coming in on router A. > The problem must be in router A... > > > All networking options (including NDP proxy, rpfilter etc.) can be > > find here http://kernel.org/doc/Documentation/networking/ip-sysctl.txt > > Thanks for that link, it's more complete than other lists I have found. > > -- > Best regards, > Reinier Boon > > > Reinier Boon | Senior software engineer | Telecats bv | > KvK Enschede 06069106 | Tel: +31 53 488 99 26 | Fax: +31 53 488 99 10 | E > mail: [email protected] > >
