The Bottom-Up Troubleshooting Approach > CCNP CIT Exam Self-Study: Selecting a Troubleshooting Approach
90% of all networking problems reside at the physical layer.
With that being said, he's loosing half his bandwidth when he plugs into his router meaning something there is off. No basic firewall is going to be able to know what hardware is plugged in and then adapt. Your getting into massive gear at that point (IE, Cisco ASA's, Pix Firewalls, MARS, ect.)
Not trying to be rude or anything, so please don't take it as such.
---------- Post added at 11:29 AM ---------- Previous post was at 11:27 AM ----------
When you are connecting to the router, are you using a physical cable or wireless?