WAN Redundancy on G2 ISR Router?

[Steven Tolzmann]

I'm currently looking over different models of ISR G2s for my company, and am thinking between the 3925 and 2911... We plan on having 2 WAN connections hooked up to the router, and use the 3rd port for the LAN. One ISP is a cable connection, and the other a fiber optic... Both have ethernet drop offs at the demarc, so I plan on using the GigabitEthernet ports.

Is it possible to setup WAN Redundancy without any protocols like BGP? What would the config look like, I couldn't find any articles on the subject, just for BGP.

Main WAN Link--------------------

                                            (ROUTER) -------------------LAN

Backup WAN Link----------------                  

Crude drawing for what I'm trying to achieve. There won't be any hosted services or any Static NAT going on either.

Thanks for help!

[blau grana · Accepted solution]

Hello Steven,

You should use floating static route.

Configure static default route with high admin distance via backup link:

ip route 0.0.0.0 0.0.0.0 backup_interface 250 name floating_static_route

Than configure IP SLA with tracking if primary link is UP. If primary link is working, default route will be instaled into routing table and this link will be used. If primary link fail, default route will be removed from routing table and default route with admin distance 250 will be used via backup link.

ip sla 1

icmp-echo IP_address

ip sla schedule 1 start-time now life forever

track 1 ip sla 1 state

ip route 0.0.0.0 0.0.0.0 primary_interface track 1

Best Regards

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