MN 500 not MN 700

Sorry, wrong product.

It is a MN 500 Router. I downloaded the update for
firmware, and installed it. At the end it said that I
had the latest version already and that I didn't need to
update.

From Router:
Current Base Station Firmware Version
Version: V1.11.017
Date: 10-03-2003

2 years old? This can't be the latest version.

Someone know what I should do?

You have the latest firmware. Nothing else to do.