On Fri, 2021-05-07 at 04:53 +0000, Senthil Kumar Nagappan wrote: > Hi Joakim, > > Thanks for your response. > > Will try to elaborate point2 with sample config. > > 1. Config at Router R1 > > lo interface > interface loopback lo has ip addr 100.100.100.125 > > eth1 > for unnumbered borrowing the lo address for eth1 and 100.100.100.126 is the > peer address > ip addr add 100.100.100.125 peer 100.100.100.126 dev eth1 > > eth2 > for unnumbered borrowing the lo address for eth2 and 100.100.100.126 is the > peer address > ip addr add 100.100.100.125 peer 100.100.100.126 dev eth2 > > 2. Config at Router R2 > Its identical to R1 config except for the loopback ip which is > 100.100.100.126 and the corresponding > peer address config for eth1 and eth2
I see, this makes sense. I wonder if this problem would affect true PtoP links as well? The only thing left then is when you have true PtoP links one does not need a remote address, that is another issue though, maybe Ondrej can comment? > > > 3. Enable ospf on eth1 and eth2 at R1 and R2 > > 4. Only one of the ospf adj will become FULL either over eth1 or eth2 and not > both > > 5. Since the peer address configurations adds a route to other end loopback > address and since the > db packets are sent as unicast, route lookup happens and db packets wont be > sent out from one of the links. > > 6. one ospf adj will be FULL and the other one will stay at EXSTART > > 7. if we use different peer address for each interface then it will work. > > Thanks and Regards, > Senthil > > > > > On Friday, May 7, 2021, 12:33:11 AM GMT+5:30, Joakim Tjernlund > <joakim.tjernl...@infinera.com> wrote: > > > On Thu, 2021-05-06 at 20:30 +0200, Joakim Tjernlund wrote: > > On Thu, 2021-05-06 at 17:09 +0000, Senthil Kumar Nagappan wrote: > > > Hi, > > > > > > I did sent this message a week back but I could not see it in the > > > mailing, moreover just now subscribed to this mailing list, so sending > > > this again. > > > > > > I’m seeing some issues with ospf adj over ptp numbered/unnumbered > > > interface. > > > > > > 1. For p2p connections, ospf should be sending only multicast packets to > > > allospfrouters, but I see its sending to unicast address. > > > (From RFC “On physical point-to-point networks, the IP destination is > > > always set to the address AllSPFRouters”) > > > > Agreed, I recall fixing the same for Quagga long time ago. > > > > > 2. For ptp over unnumbered interface, bird requires peer address > > > configuration which is not required from the ospf perspective. Because > > > bird is using peer address and > > > sending > > > unicast packets, bird cannot form multiple ospf adj over ptp unnumbered > > > interface between 2 endpoints using same peer address. > > > Made some quick changes and have attached the patch that addresses the > > > issues. Relaxed the source ip address validation for ptp link in packet.c > > > for now. More validation > > > can be > > > added to make it complete. > > > > I don't quite understand what you are saying here, can you elaborate? > > > > One thing I recall, BIRD OSPF seems to always require dest IP address for its > routes. For a PtoP I/F > this is optional/not needed so I guess this is a bug in BIRD. Possibly > because of bug 1) > > > Jocke >
