DHCP Problem?!

[timbeullens]

Hi all,

Yesterday I experienced something strange:
Suddenly some of our computers could not connect the internet properly, and some connected just fine.
I also noticed that ALL computers could connect with

http://www.google.be

and could search google on a normal way, but if I entered a url in the browser, or followed a link in the google searches, no connection was made.

I figured out that it was not a DNS problem, as I first thought. All our computers have the same network settings, are connected via the same internet connection and router,…

I tried to connect computers straight on the CISCO 800 series router of our DSL connection, and still the same problem. Than I entered an IP address manually and….IT WORKED!
Strange since there was also the same problem when I tried surfing from one of the servers (of course with a fixed IP)
I decided to restart the DHCP server (a win 2000 server) and throw away all the lease records.
Afterwards everything worked fine again.

I CANT see why and where this is a DHCP problem, Why with some PC’s it did work, and with others it didn’t.
Why could I reach google easily and no other website?
Why did it not work from a server with fixed IP?

I really would like to understand this problem.

Anny Idea’s anyone?
Greetz!
Tim

 

[Davetoo]

To the contrary, it indeed sounds like a DNS problem since you can enter an IP directly and it will work but it won't resolve a name.

Confirm your DNS server settings are correct on the clients.

I'm Certifiable, not cert-ified.
It just means my answers are from experience, not a book.

 

[timbeullens]

I checked the DNS service:

i surfed to the IP address of our corporate website as well in stead of the url--> same thing.

Also pinging to url's where possible, but when I entered the URL in the browser it didn't do annything. (also the IP i 've resolved by pinging did not work)

So i don't believe it was a DNS server.
Also the working PC's where pointed to the verry same DNS servers as the PC's that didn't work. (those from our ISP)

 

[dberg35]

Is your server the DNS server? If so you need to put your ISP DNS servers in your DNS forwarder and in your router set the DNS to your servers IP address.

 

[timbeullens]

The DNS servers are the ISP servers.

there are no other or additional DNS servers in my network.

so far the problems are solved (was solved within the hour)
But i want to understand what happend so I can avoid this ore act faster and with more precision the next time.

 

[GlenJohnson]

Are the clients all the same OS? (If you can't recreate the problem, it's not solved. It will come back you bite you again.) You need to find out why some pc's were affected and not others. Good luck.

Glen A. Johnson
If you like fun and sun, check out Tek-Tips Florida Forum
Don't forget to Buckle up. It works.

 

[timbeullens]

Yep, all XP-pro.All dell latidude 620 portables.

The strange thing is that there is no diffecerence between working and not working PC's Not in config and not in hardware.