2 ISP, 1BGP and 1 static route question

[mattM26]

Hi All,

We have 1x 4331 router that is connecting to 2 different ISPs, from ISP A we have BGP setup with them and ISP B they're just giving us a static route. As of now, on the 4331 there is a default route to 0.0.0.0 via the static route for ISP B and everything is working fine. My question is, lets say ISP B goes down do I need to do any SLA/tracking on that interface so that the BGP routes from ISP A will kick in? Right now I don't see the BGP routes on the routing table.

Thank you!

[MHM Cisco World]

If the static route point to egress interface and this egress interface is DOWN then static route will remove and BGP must inject into routing table 
if the static route point to next-hop and your router can not detect next-hop failed or not then you need IP SLA. 

the ONLY think make this not work 
that other BGP PEER is learn from static route, are this is case here ?

[mattM26]

got it! so if i were to physically unplug the cable going to the ISP B (static route) the backup ISP sing BGP will kick in? 

and if the upstream ISP goes down while the interface is still up, then IP SLA is needed to see if the far end is reachable?

[MHM Cisco World]

Yes router must know that this static route is not active, in routing protocol the hello message and other message do that, but for static route 
either egress is down 
or 
next-hop with IP SLA is unreachable

[Flavio Miranda]

Hi

 "We have 1x 4331 router that is connecting to 2 different ISPs, from ISP A we have BGP setup with them and ISP B they're just giving us a static route."

 If they are sending to you a default route, then you must be using some dynamic protocol with them, no?  Otherwise, you should add the route on your router with the command  "ip route 0.0.0.0 0.0.0.0 ISPB" You check it with the command "show ip route static"

"As of now, on the 4331 there is a default route to 0.0.0.0 via the static route for ISP B and everything is working fine. My question is, lets say ISP B goes down do I need to do any SLA/tracking on that interface so that the BGP routes from ISP A will kick in?"

If they are passing down this default route to your router and they become unavailable, the route will desapear from routing table. But, if this route was add on your route with "ip route " command then, the route will stay there.You can use Tracker to change the "static route" default Administrative Distance in order to BGP be more interesting.

"Right now I don't see the BGP routes on the routing table."

You could share the config here. But, you can also check by yourself if BGP config is Ok. You can run "show ip bgp summary" and "show ip bgp neighboard"  just to make sure the connection with ISPA is OK.

  You can also run "show ip bgp neighborad ISPA received-routes"