Getting wrong ip address from local gateway when doing network lookup

So I've been running into an odd problem. About a month ago, I noticed that I could no longer connected my computers on the network by typing their name, e.g. typing \\laptop from my desktop. Currently I can connect to my desktop from my laptop in that manner, but I still can't get to my laptop from my desktop. However, if I type in the laptop's IP address, such as \\192.168.1.76, it works. The same happens in programs.

This is a headache because I synchronize my files between them, and there's a lot less config long-term when I can tell the software a computer name to sync with rather than an IP address. Also it's sorta annoying to have to do an ipconfig /all on the laptop before connecting to it from the desktop.

So tonight I was digging a bit, and found via ping and nslookup that apparently those commands are getting the wrong IP address. Ex. if I do ping \aptop from my desktop, instead of 192.168.1.76 (the address the laptop is using according to its ipconfig), ping uses 192.168.1.70. Even on the laptop, while ping laptop will work (it's all local to the machine then), if I do ping laptop.[the gateway of my network], it gets 192.168.1.70 and fails to ping itself. Nevertheless, if I view the laptop's details on the router's intranet site, it gives its IP as 192.168.1.76, which I believe is the correct one.

I've already done an ipconfig /flushdns NetBIOS is also enabled in the WINS setting for advanced network config.

The problem started when I was on the network I am on now, but when the two computers were on a different network with a different router for a few weeks, it still persisted. The desktop runs XP x64 and the laptop runs XP Home. The desktop is connected over Ethernet; the laptop is using WPA-protected wireless (the router config reports WPA-PSK (TKIP) and WPA2-PSK (AES) authentication). Both can access the Internet just fine, both copying files from its shared drives and pasting files to them - the desktop can only do the same when communicating by IP address, however.

Currently, no security software is enabled on either computer, including firewalls. So I reckon that probably isn't the cause. Obviously I'd like to get some of that back up, but for the purposes of debugging this issue I've disabled them.

So my question is... how come ping, nslookup, and apparently other programs such as Explorer and my backup software are getting the wrong IP address for my laptop?

 

First check the router to make sure you aren't setting incorrect hostnames (or static IP leases) there. Make sure you aren't using lmhosts, because it overrides everything else.

On each computer check your netbios name table with nbtstat -c and see if the wrong address is showing up there as well. If it is, run nbtstat -RR on each.