How Config Redundant links to single NIC/IP Address?

RobinCruz · ‎01-13-2009

How can one configure a network to have redundant links to a single NIC or MAC address? This would be called fault tolerant so that if one link failed the other link would still provide data. This would be 2 100BaseT links from a router/switch to a single NIC/IP address.

Would one duplicate data be sent and the receiver somehow select one or the other or would the router reconverge to the redundant link by sensing a link failure and reconveging to the backup?

Any thoughts or literature you might refer me to so that I could understand how to do this or if it can be done?

Thanks for any tips

Collin Clark · ‎01-13-2009

A single NIC won't work, there is no redundancy there. You'll need two NIC's. There are multiple names for it and here is a reference.

http://en.wikipedia.org/wiki/Link_aggregation

rkruz1234 · ‎01-13-2009

Thanks for that. Is there some way the destination router can do the switching between and active and a failed link to the single NIC interface?

this for 2 physically diverse and identical links, switched to a single hosts NIC.

Collin Clark · ‎01-13-2009

You would have to setup a monitor within EEM and if the test fails, the router can perform an action (like change a route). There are some really sharp guys in the Network Management forum. They could help if you run into any problems.

http://www.cisco.com/en/US/products/ps6815/products_ios_protocol_group_home.html