Hannes, thanks for your reply. It was indeed rp_filter (found it myself). What changed were the default settings in Ubuntu (07.04 to 14.04).
Regards Joerg 2015-10-13 15:18 GMT+02:00 Hannes Frederic Sowa <han...@stressinduktion.org>: > On Tue, Oct 13, 2015, at 08:47, Jörg Pommnitz wrote: >> Hello all, >> I'm moving an application from 2.6.23 (yes, it's ancient; that's why >> we are moving) to 3.18LTS. The application monitors multiple network >> links to the same target with ping packets. The different links are >> selected either by their next hop router (Ethernet) or the network >> interface (Point-to-Point links, aka cellular data). >> To force different routes to the same target, the outgoing packets are >> tagged with different firewall marks. Then I'm using routing rules to >> select different routing tables with different routes for the same >> target. >> The outgoing path works perfectly fine in both, 2.6.23 and 3.18. >> However, the same is not true for the incoming ICMP replies. They are >> incoming; I see them with tcpdump. But some packets do not get >> delivered to user space in 3.18. I'm not 100% sure, but I think this >> happens if there is no "normal" route to the ping target, e.g. the >> source address of the ICMP replies. This looks like some kind of >> misguided ingress filtering that keeps packets out if a normal routing >> lookup fails. >> >> Am I on the right track? If so, is there a way to disable this >> filtering? If not, what could cause this changed behaviour? > > Did you disable rp_filter? Sounds like it, but 2.6.23 also had it > activated by default, so maybe you missed the option in sysctl.conf. > > Bye, > Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
