Interaction of OSPFv2 and PtP tunnels (bug?)

[Soha Jin]

Hello LEdoian,

You may try 10.1.0.1/30 and 10.1.0.2/30 for tun0 on both ends.

`10.1.0.1 peer 10.1.0.2` means the interface is connected to a network 
`10.1.0.1/32`, but 10.1.0.2/32 is also reachable directly on this 
interface. So only 10.1.0.1/32 will be selected by OSPF, 10.1.0.2/32 
needs to be imported by `protocol direct`. You can take a look with `ip 
route` in your netns, there will be something like `10.1.0.2 dev tun0`.

I am not sure why adding a stub flag on interface will make it works.

By the way, you can use /31 for inter-router links (RFC 3021), which 
will make calculations easier. Network address and broadcast address 
will be ignored in /31 subnet.

Regards,
Soha