I was doing a lab that included the next-hop “verify-availability” config, and I had a general question about the sequence part of the command. I can’t find any Cisco documentation that lays out specifically what that does. For instance:
route-map PBR permit 10
match ip address MY_ACL
set ip next-hop verify-availability 10.1.2.3 1 track 1
I understand that this is triggered when an IP from MY_ACL is matched, at which point it checks the tracking object (likely an IP on another router) before setting the next hop to 10.1.2.3, but what I’m not clear on is what the sequence does. Is this for multiple tracking objects?
You can find detailed information about this command at the following Cisco IOS command reference documentation:
The verify-availability keyword by default uses CDP to verify that the next hop is reachable before the device attempts to policy route to it. With some additional keywords described in the documentation, you can change this default behaviour and use object tracking to verify reachability before policy routing to the next hop. Object tracking is being used in the example you provided in your post. Both of these options are described in detail in the linked documentation.