I don't know if this will repro on other systems. Here's what I saw:

Vista Business Edition is a member of a small AD (DC's are W2003 R2).
Vista's networking setup for the (hardwired) NIC; DHCP, all defaults. The
DHCP servers only have three options set for the scope: 003 router (the
gateway), 006 DNS servers (2, both AD DCs), and 015 DNS domain name (the AD
domain name). At an earlier date, the system had a DHCP address of 10.x.x.59;
later it ended up with 10.x.x.57 address. There was no DHCP reservation; both
are dynamic addresses from the pool.

The problem: even though an IPCONFIG /ALL would show only the 10.x.x.57 IP,
I'd do an NSLOOKUP on the system's name; it would return both the .57 and .59
addresses and if a roundrobin setup. If I were to go into DNS server and
manually delete either the .59 or BOTH the .57 and .59 addresses, they would
come back if I ran IPCONFIG /REGISTERDNS on the Vista client. DHCP would
still have no lease or registration for the .59 address. Essentially the .59
address was 'phantom' existing only as a DDNS registration.

What finally solved this, for me:

1) wmic nicconfig where ipenabled=true get settingid, Ipaddress
(to list the current ip address and GUID for the NIC)

2) navigate to the following key in regedit:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Tcpip\Parameters\DNSRegisteredAdapters

3) Remove all GUID's not listed in the revious WMIC output (step 1).

Viola! Vista no longer registers a 'phantom' IP in DDNS. I do not know if
the failure to delete the DNSRegisteredAdapter key when the old DHCP address
stopped bing used is a BUG, or a FEATURE, or just an odd and random
occurrence for my system, but I thought I'd report this anyway.

Cheers,

-quux




----------------
This post is a suggestion for Microsoft, and Microsoft responds to the
suggestions with the most votes. To vote for this suggestion, click the "I
Agree" button in the message pane. If you do not see the button, follow this
link to open the suggestion in the Microsoft Web-based Newsreader and then
click "I Agree" in the message pane.

http://windowshelp.microsoft.com/com...orking_sharing