We setup two Cisco ASRs as edge routers, each with a connection to a unique upstream ISP. Both routers are advertising the same IPv4 /24 prefix to their ISP via BGP, and both are connected to the same LAN. No further configuration has been done.
It seems to be working fine right now, although the routers have different IPs on the IPv4 network, e.g. R1 is 18.104.22.168 and R2 is 22.214.171.124. I believe this will cause problems when 126.96.36.199 is down, and hosts inside the network are trying to go out through the /24's default gateway, which will always be 188.8.131.52 and never 184.108.40.206.
The goal of having two routers and two ISPs is to achieve redundancy for both incoming and outgoing traffic, in case one router or ISP fails.
Does VRRP or HSRP apply to this scenario? Is iBGP between the routers required to set them up? Can incoming/outgoing redundancy be achieved without one of those protocols?