As in external to the Internet? There are a few utilities to do it, but an easy way to find out is to go to http://visualroute.visualware.com and you should see your external IP listed on the button next to the IP entry box.

Yes, internal -> within the Intranet and External ->Internet.
 
Clutch, the IP address listed in the Visual Route Server is different from the IP address that my NW admin gave me...any clues why? Additionally, any tools to verify the same?
 
Thanks.

That is going to be the IP that your network gets to connect to the Internet. This would be similar to the IP that you get when connecting from home with a modem. As for why it's different, I don't know. I am not familiar with the specifics of your network, so at best it would be vague speculation (like NAT pooling, DHCP from your ISP, etc).

Yes, you are right that what you see in the Visual Route Server is the address to which the network is connected to the service provider (usually through ADSL modem or whatever) and not the Firewall which is one step lower than the modem.
 
So my rephrased question is how do I find out the IP address of the firewall that is connecting to the modem, if I know the IP address of the firewall as seen by the office internal network......

The only thing I would suggest is connecting to the firewall and asking it directly via its mgmt software.

https://www.asc.wpafb.af.mil/faq.html#access

DosFreak,I am unable to access your link!