I know it can be used to create a logical separation so, for instance, have 4 gateways with the same address, there’s no conflict (it sort of relates to my goal, one second…).
My intranet subnets are routed using a router (no kidding !) but it’s only a router, not a router-firewall-toaster combo or anything of the sort. Upstream from the intranet’s router, the transit network is also the backbone OSPF area connection to other routers and the firewall through which upstream continues to the public network—it’s daisy chained.
To add VyOS into the mix, I want it to interface directly with the intranet router’s interfaces, replace OSPF with VRRP and connect every interfaces of every network device to VyOS and move the WAN link to it. Then recreate the daisy chaining in software with VRF.
I have tons of information on how VRF can make unambiguous two or more gateways with the same address, however, I have not not found any information about how it would treat information circling around and if it’s not going to try to route it directly and thus asymmetrically.
I made a little diagram to help me explain: