OSPF over SSTP - works great but why?

RouterOS Beginner Basics
1

Hi everyone,

I have less a problem than a question of understanding. The issue is that I have set up an SSTP tunnel between two MikroTik routers (CHR and RB 4011) and, based on this, OSPF is running in point-to-point mode and advertising networks.

As far as I know, OSPF uses multicast (224.0.0.x) in broadcast and point-to-point mode to send hello packets, set up adjecancies, etc. And furthermore, I assume that PtP VPN tunnels like SSTP do not transmit multicast traffic.

So my simple question would be: why does this work anyway?

Thanks in advance

2

They do transmit multicast. You can do OSPF over any PPP tunnel in point-to-point mode. Most likely the packets to the multicast address are simply “flooded” across the PPP tunnel, and therefore treated much like unicast to the other side.

3

@Chaosphere64

Does SSTP into ospf network? if yes, what you expecting?

4

So then I was probably wrong about that point.

Thanks for clearing things up!