Scott Nicholas
2017-12-03 21:01:35 UTC
I joined a VPN network (dn42) to learn BGP and such and decided to do
so with OpenBSD, which I'm also learning. Most peers are Linux
machines and they re-use their address on each VPN tunnel as a /32. I
have been successful doing the same until I decided I needed ospf for
my internal routes.
openospfd sets the interface (identified only by its IP) as the
multicast source. Since several tunnels have that address, it sets it
incorrectly. A brief look at Linux headers show that their newer
ip_mreqn struct includes an interface index since Linux 2.2. Perhaps
this is a useful inclusion in the OpenBSD kernel so that userland can
pick the interface correctly?
For now I've worked around this by assigning /31 aliases in
192.168.0.0/16 to the interfaces. But I'm curious what others are
doing that use OpenBSD as a router, as it's all fairly new to me. I'm
reading that OSPF could also have unicast neighbors setup, but
OpenOSPFd doesn't have this feature.
so with OpenBSD, which I'm also learning. Most peers are Linux
machines and they re-use their address on each VPN tunnel as a /32. I
have been successful doing the same until I decided I needed ospf for
my internal routes.
openospfd sets the interface (identified only by its IP) as the
multicast source. Since several tunnels have that address, it sets it
incorrectly. A brief look at Linux headers show that their newer
ip_mreqn struct includes an interface index since Linux 2.2. Perhaps
this is a useful inclusion in the OpenBSD kernel so that userland can
pick the interface correctly?
For now I've worked around this by assigning /31 aliases in
192.168.0.0/16 to the interfaces. But I'm curious what others are
doing that use OpenBSD as a router, as it's all fairly new to me. I'm
reading that OSPF could also have unicast neighbors setup, but
OpenOSPFd doesn't have this feature.