In a lot of situations you have several routers or switches you want to have configured in a similar way. Say you have 12 routers at different branch offices there will be parts of the configurations you want all those routers to share.
I had been looking for a tool which could do this for me but could only find programs which compared two files to each other. I needed a tool which could compare several configurations against each other.
I ended up creating a script to compare network device configurations.
Hopefully it will be useful to you.