Re: BGP Multihop across Fortigate
Firstly thanks again for the stacked vdom suggestion and link, I do think this is the best option. The reason I mentioned a route-reflector is that I'm looking for a way (using iBGP) of getting routes from the normal vdoms to be known within the root vdom - the root vdom would be the route-reflector server. In your example, you used a static, but I would prefer iBGP. Presumably there is no problem running iBGP across the virtual links? Since the switches at either side of the FW use the same AS number, I believe we'll need a route-reflector because iBGP won't announce routes learned from another iBGP neighbor to upstream iBGP peers (the "full mesh" requirement)?
The background here is that I have an EVPN network with the FGT acting as an inter-vrf segmentation firewall (i.e. the firewall allows the traffic to hop VRF to exit the fabric via a default route). The reason for BGP is than EVPN requires it so I wouldn't need to redistribute into OSPF at any point. Your stacked approach would potentially allow N+1 external peerings, whereas the non-stacked approach would involve N*2 external peerings (where N is the quantity of VRFs on the fabric).
Thanks for your time.