I'm considering deploying Multi Path TCP for some of our public facing services.
If you're not familiar with the concept, the basic idea is that the initial connection is done on IP 'A', then several other connections are then negotiated and opened on IP 'B'/'C'/... and those should use alternative path.
The way I was thinking of doing it was to have the initial IP 'A' be a PI IP range that I advertise via two uplink providers. Then the alternative paths 'B' and 'C' would be PA IPs of each of my provider and obviously need to be routed to the correct one.
The server machine would be in 3 VLANs, the main dual advertised one, then one for each of the providers PA IPs.
Question is how I can tell the switch to route back the packets coming from the PAs to their respective providers. Policy Based routing isn't supported AFAICT. I could put each VLANs in a different VRF. But only the 'main' one would have the BGP sessions and inter-VRF route leaking isn't supported. Can I manually put a route in the other two VRF that use a gateway that's in the main VRF ? (it would be manual and not through BGP).
Any other way to accomplish this ?