[c-nsp] Nmap(way ot)

[Kern, Tom]

I was running nmap internally against my cisco 1700 internet router.
i have a watchguard firebox x 1000 sitting between my network and the internet and router. 
here's the wierd part- everytime i run nmap against the router, i get the firebox as the os fingerprint and the ports open on the firebox.
i get the same result running nmap against my home network or yahoo.com or any host.

the firebox will autoblock any ip's doing port scans externally against your internal network but won't block anything going out so i think this is very strange.
i was wondering if anyone out there would have an idea as to what the issue could be.
i know this is OT and i apologize. i'm just stumped.

thanks alot