On Thu, Dec 24, 2009 at 12:38:07AM -0800, Xin LI wrote: > Hi, > > A friend of mine has encountered some problem in his setup which > consists a pair of GRE peer, one running on OpenBSD and another > running FreeBSD 7.2-RELEASE; with 7.2-STABLE, there is no improvement > over the situation. The problem we have observed seems to be related > to GRE packet not being routed as observed, here is some details: > > - The FreeBSD box has one network interface connected to two (2) > upstream network, with different IP and does not belong to the same > subnet, say, one is 1.2.3.4/24 and another is 5.6.7.8/24 > - The default gateway can be reached through the first IP address > bound to the network interface; > - An explicit route has been configured to the OpenBSD host, the > gateway being used can be reached directly via the secondary (aliased > 5.6.7.8/24) IP. > - Both the default gateway and the explicit host route can reach the > OpenBSD route. > > The problem they had is, while traceroute to the OpenBSD host can give > the desired result, however, packets that is supposed to be > transferred through the GRE tunnel, while they will be encapsulated > into a GRE packet, the GRE packet itself won't go to the explicit host > route, but end up going to the default gateway. > > The friend has configured his switch to "bounce" the packet back to > the server by configuring a host route on L3 switch, and it seems that > the FreeBSD box is able to route the GRE packet to its desired gateway > this time. > > Any suggestions? >
gre(4) is caching the route to the destination on creation time (when the ifconfig greX tunnel src_addr dest_addr command is issued). So you need to create the host route to the openbsd box before configuring the gre tunnel. It should be possible to reconfigure the tunnel-endpoints which should redo the route lookup resulting in a correct routing. -- :wq Claudio _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
