We are using two WAN links Airtel (MPLS) and TATA (P2P). Default gateway in Switches is 10.7.251.1 (AIrtel link router). So all the traffic flow is thro Airtel router. We routed some traffic to TATA link from there. When the Airtel link is in UP state as per the routing thr data flow is wright. but when the Airtel link goed down the routed traffic after reaching TATA router (10.7.251.18) terminates and we are unable to connect the external network.
Routing at Airtel router
We need use this TATA link even when this Airtel link went down. Please help me
ip route 192.168.61.15 255.255.255.255 10.7.251.18
ip route 192.168.61.161 255.255.255.255 10.7.251.18
ip route 192.168.61.163 255.255.255.255 10.7.251.18
If you have configured static routes pointing towards Airtel router, no matter what the switch will always route the traffic to that even if there is failure at WAN.
Consider deploying two static routes (floating as we call) from your switch to each ISP
ip route 0.0.0.0 0.0.0.0 interface to ISP-A 10
ip route 0.0.0.0 0.0.0.0 interface to ISP-B 150
Together with Reliable Static Routing Using Object Tracking solves the problem. Enhanced Object Tracking introduces a generic track object that can track a state of an interface (layer-2 or layer-3 state), presence or metric of an IP route.
Configure ip sla object pinging a next hop address or even a any address reachable via the Primary link
ip sla 10
icmp-echo x.x.x.x source-interface <>
ip sla schedule 10 life forever start-time now
Create a track object monitoring the reachability of the SLA target
track 10 rtr 10 reachability
After configuring the track object, attach it to the primary static default route to ensure that the default route is removed if the SLA object is not reachable
ip route 0.0.0.0 0.0.0.0 interface to ISP-A 10 track 10
The reliable static routes silently appear or disappear from the IP routing table based on the state of the attached track object which will help you route traffic out the TATA link in case the Primary link fails.
Also prabha..... If you have two diff routers to connect to the ISP's... you can have the HSRP between the LAN end routers to acheive it.....
Bharthi to LAN rtr A
Tata to LAN rtr B.
If you are running bgp then you need to define a metric for the primary and backup accordingly.
Please rate if the given information helps.