I have one static IP from my upstream provider and I want to implement some redundancy at my core.
Here is the proposed configuration:
So essentially the two routers have the same WAN address (1.2.3.4) and the PC will use 1.1.1.1 internal as its gateway (VRRP address).
I’m guessing you guys will say this won’t work with two devices having the same address (1.2.3.4) on the same LAN segment. Maybe a script coupled with the VRRP config can activate the WAN address on the second router whenever the backup router kicks in?
If this doesn’t work, please let me know how to accomplish this another way. Again, one static IP from the provider.
You can’t have two routers with same IP address on same LAN segment. Well, you perhaps could, if it was just for simple routing with no stateful stuff (NAT, connection tracking in firewall) and you wouldn’t need to communicate with this specific address, only with routed subnet behind it. With these conditions, it should work ok. Except that if there was something watching for strange things happening in that network segment, it would go crazy.
You can:
a) Use your internal VRRP + script idea.
b) Put another VRRP on WAN. You do need some other addresses on WAN to use for VRRP communication, but they don’t have to be from same subnet as the virtual one. You can use e.g. some private 10. and it will work.
