Anyone know what would be using this port? The system that's spitting out thousands of requests is a Lotus Notes SMTP Mail Gateway. It is configured as a published web server thru ISA...but ISA is blocking all its attempts to connect to various systems using UDP 137. Its certainly not mail...as all the servers functions are acting just fine. Brian W. Rogers MCSE, MCT, MCP Client/Server Network Developer Tree of Life Corporation rogersb@xxxxxxxxxxxxxx office: (904)940-2152 mobile: (904)806-7173