never heard about “PPtPA” before.
can you be more Specific, please?
what do you need to do ? more than one Ip-adresses, assigned, dhcp management/deployment or anything else ?
You can fudge things a bit and make it work, but you can’t just go put a /31 on there.
I forget the procedure, but Mikrotik chimed in on another thread here last year with the work-around.
I think it was a thread about feature request for /31 support or something similar to that.
EDIT: The procedure is to set local end to /32 and network=remote IP
This creates two /32 routes in your routing table, and I think OSPF gets mad… I guess I should fire up GNS3 and test.