I wish to configure HSRP and BGP multihoming with failover and I request configuration steps from experienced professionals of this forum.
I am also attaching diagram of network.
I wanted to implement HSRP between R2 and R3 in Head office with tracking Serial0. R2 with ISP-A is primary link to reach incoming and outgoing internet traffic and accept traffic from internet destined for Server1 hosted inside network. If Serial0 of R2 to ISP-A gets down or complete R2 failure the outbound traffic should flow from R3 to ISP-B and come back the same route.
We have total of three internet connection. Head office has connection from ISP-A and ISP-B one connection in Disaster Recovery site (DR Site) from ISP-B.
The order to use of these connections are ISP-A is primary link and in the event of serial link failure or router failure (HSRP) the traffic should flow from ISP-B to internet and if both ISP-A and ISP-B is not available (meaning disaster happened) then the traffic from internet to Server1 should flow from ISP-B via DR site.
R2 - ISP-A = Primary link for incoming and outgoing traffic
R3 - ISP-B = Secondary Link for incoming and outgoing traffic
R4 - ISP-B = Tertiary link for incoming and outgoing traffic