I am currently troubleshooting an issue wherein we are experiencing a flood of NETDDE registrations on our WINS server thru port UDP 137. What happens is, when clients logs in on the network and failed to get a DHCP IP lease, a NETDDE error is generated that causes WINS releases and registrations to continously hit our WINS servers.

This NETDDE error is normal if the lower ip stack for some reason had to lost connectivity which sends a trigger to WIndows to unbind the upper stack protocols and bind again when the IP stack gets restored.

Shutting down the NETDDE service disables the abnormal traffic. Has anybody experience these issues?