I just got a router and there's a plate on the bottom (required for the dust extractor attachment) which has a hole in it with a raised circular wall that protrudes beyond the level of the base. Is this normal? It seem like it will get in the way, but I don't want to do anything about it if it's supposed to be there.
From the comments:
This is referred to as a bushing or guide bushing (occasionally a collar), used for various routing tasks that involve templates of one form or another. It should be described clearly in the documentation that came with the router, although it will only give you a hint as to how it can be used.