FastEthernet working as a backup interface

[mercedesm]

I need to configure a Fast Ethernet interface as a backup interface of a serial interface. I can enter the command but I need to know if this feature is supported by Cisco TAC. Where can I find information about this?

[davidjmeier]

Yes, it will work.

Here is a link to Cisco backup example (however it is using serial with a bri backup - but it will be similar, obviously without DDR).

http://www.cisco.com/warp/public/129/bri-back-dp.html

Hope that helps and good luck!!!

[mercedesm]

I am a bit worried about the backup interface being a FASTETHERNET interface. I know it works but I need to know if it if supported by Cisco TAC.

Some time ago, I open a case about a Fastethernet interface being backup of another FastEthernet interface. Cisco TAC engineer asked me that even if it works, it is not supported by Cisco TAC. I wanted to know if I will have the same problem.