DNS resolver issues - NSLOOKUP works, Ping doesn't

I've got a strange one on a Win 7 Pro machine - it can't connect to any websites by name which obviously points to a DNS issue, and testing further it's all services, not just websites. I've done the usual checks that it's getting the right DNS entries from DHCP, tried an ipconfig /flushcache, disabled IPv6, all the usual things. But it comes down to this:

ping <hostname> fails to resolve

tracert <hostname> fails to resolve

nslookup <hostname> does resolve but doesn't cache it so that a future ping works.

tracert <ip> resolve and gives the fully qualified hostname

No firewall issues or any security software that's unusual to this machine.

Does anyone have any ideas?

Have you tried reseting the ip stack?
http://www.geeksinphoenix.com/blog/p...Windows-7.aspx

First thoughts - are you pinging the Fully Qualified name? If not try that. If that works then you should look at the DNS suffix on the network card.

Jonathan

Quote:

---

Originally Posted by SYNACK

Have you tried reseting the ip stack?
http://www.geeksinphoenix.com/blog/p...Windows-7.aspx

---

Good call, but sadly it hasn't changed anything.

@Jonathan

Yeah definitely using the FQ name.

I've also found that ping -a <IP> will return the host name.

Have you got WINS configured?

Try
nbtstat -c

Is anything showing in the cache?

Also, have you got a second network card configured to a wrong (or no) DNS server?

Another thought - the NSLOOKUP is tuned into the correct DNS server (your internal one)?

This is old but I think it's still current. At the very least it's informative.

Microsoft TCP IP Host Name Resolution Order

Yep WINS is in use, configured like every other machine (by DHCP)

We had an issue with the search suffix being deleted from our tcp\ip settings. Or rather an entry being made that erased the default.

Do a search for "SearchList" under regedit and see if it exists and if it does what it's been set as.

Probably this issue: http://www.edugeek.net/forums/window...m-entries.html

Computer Configuration -> Administrative Templates -> Network -> DNS Client -> “Allow DNS Suffix Appending to Unqualified Multi-Label Name Queries”

Win 7 has a different default behaviour compared to XP.

HI

I know this will be a daft question but have you tried fixing the ip for tests only and test agiain. Have you tried a different nic and a different network cable and port. I had a switch refuse to work correctly and it had be be rebooted after a surge. Have you tried updating nic driver.

My last idea would be if you have several machines of the same type and model move a working os hard drive from a working machine into this same make and model and try that it will tell you if its a hardware problem. If you dont have a similar machine try a linux boot cd and it will tell you if its hardware of software.

Richard

I had the exact same issue on a win7 pro.
I managed to solve the problem after reading the posts made in this topic. It was making me crazy and I was gonna reinstall windows!

Not sure what the problem is and what causes it but I solved it by replacing the following registry entries. I replaced them with the entries form another working PC
U can do the same or just use the fix.reg file I attached. Just make sure u change "Hostname" and "NV Hostname" entries with ur PC name. U might also want to take a backup of those registry entires.
Attachment 10910

Here is the regsitry address:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\servic es\Tcpip\Parameters]

Instead of CurrentControlSet u might see ControlSet001 or 002. I replaced those too.


Hope this helps

Nothing in the cache as reported by nbtstat, and no joy with those local policies. It's all addresses, not just the addresses of servers on the network here - the machine can't resolve google.

I've checked nslookup is pointing at the same DNS servers that everything else is and it still manages to resolve names.

I think a LiveCD might be a good next port of call

Is your machine fully patched and up to date? I had some inexplicable network problems (some scripts just stopped working on machine startup) which were resolved by the updates.