TCP Connection nt ending

We are using windows server 2003

These connections are not ending even with the conneting machine turned
off??
TCP 10.1.50.17:23 192.168.15.152:1096 ESTABLISHED
TCP 10.1.50.17:23 192.168.15.152:1266 ESTABLISHED

If I try to ping from 10.1.50.17 I get
Pinging 192.168.15.152 with 32 bytes of data:

Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 192.168.15.152:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

Also if I try turn on the affected machine I can not ping the server
How can I end these TCP connections.


I have changed the ip address of the affected PC and can now connect to the
server. But besides rebooting the server how can I end these connections.


Kevin Bilbee