Hi, Can anyone suggest me a method to find the previous hop router's outgoing IP address? that is, given a packet forwarded by R1 to R2, R1<------>R2<-----> R3 how might R2 find out the IP address of the outgoing interface of R1? I have access to skb->dev, which points to the packet's incoming net_device on R2. Obviously, there should be a way to do it though the routing protocol, since each router keeps info about its neighbours. ButI dont know about the implementation in kernel 2.4. I thougth of two other ways which arent that convincing: 1) R2 can do a reverse lookup in its arp cache (but is there a guarantee that there will always be an entry for R1?) 2) Use ip_route_output_slow() to find the next hop for the packet's original destination. (but then routes may be asymmetric..) Is there a simple way to do this? TIA Akshay __________________________________________________ Do You Yahoo!? Get email at your own domain with Yahoo! Mail. http://personal.mail.yahoo.com/ - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org
