Can not Ping WAN

[PlsHlpKat]

We have a WAN made up of 4 LAN's located in 4 different States. Connected through VPN All locations running WINNT 4.0 Server, and various Client software (Win 2000, WIN98 mostly). There is a strange problem at one of our locations, 5 out of about 25 client machines cannot ping outside of their LAN, and we cannot ping them. They have Internet access and there mail is fine, they can see all of there local machines but not beyond that. We run TCP/IP protocol and everything appears to be set correctly. Does anyone know what could be causing this or any suggestions on where I could go to find an answer.

Thanks!! Kat

 

[justcurious]

Is it possible these five machines are on a common switch that is seperate from the rest of the LAN? If so, it's possible that the switch is set to prevent pings.

 

[PlsHlpKat]

No the switch is fine but I did just notice that the 5 users are not listed in the DHCP Manager. Could the problem lie there.

 

[justcurious]

Well, it is a common denominator so it's a place to start.
However, if they can see the Internet and their mail server, they obviously have valid IP addresses.

Is it possible they have static IP information in their network settings? Could it be that there is a second valid gateway address on that LAN which they might be using?

Did you recently change the gateway address for the DHCP scope and their leases have not expired?

If their network settings are properly configured for DHCP, have them run ipconfig ( maybe it's winipcfg in Win98, I can't remember ) and release and renew their leases.

 

[PlsHlpKat]

They are set to obtain an address automatically. When I try to release and renew their IP through winipcfg it tells me there is no DHCP Server available?

 

[justcurious]

This just keeps getting more fun as we go along, doesn't it?

It has been a couple of years since I have had to deal with this kind of thing so I will have to do some thinking and reading.

In the mean time:
Check your DHCP scope and make sure the address range is large enough to satisfy the number of computers making requests.
Check the active leases and delete any that indicate a "bad address".
Try releasing and renewing the lease on one of the machines that is not having the problem. If they then cannot see the DHCP server, suspect it!
Cold boot the five machines in question.
Hopefully some other MS certified/experienced person will come along and offer their two cents worth.

 

[PlsHlpKat]

Thank you, I did do all of the above. It appears to be a problem with the DHCP. I noticed there were some unnecessary excluded ip addresses but still ample addresses to cover requests. I did delete the "bad address", then I tried to release and renew on a good machine and got the same message DHCP Server unavailable. Then I had to set a static ip because I could not log into the network? I have checked the settings on the DHCP Manger, and everything appears to be set correctly. It appears that as leases expire no address is being issued.

PS I still cannot ping the five machines from my WAN and still can ping them from the LAN??

Kat

 

[justcurious]

Is it possible the VPN software on these machines is configured incorrectly?

Have you moved your DHCP server to a different network recently? Have you made any changes to the server hosting the DHCP service recently?

Since DHCP requests are broadcast from the workstations, they do not route. If they are not on the same LAN segment as the DHCP server, then a DHCP agent must be installed on one computer on the local LAN. A DHCP agent picks up the broadcast requests and forwards them across a router to the known IP address of the designated DHCP server.

 

[kida]

real quick question... have you ever been able to ping these workstations? If so, what has changed?

 

[kida]

any chance this could be something simple? The ping command uses a hyphen to flag command-line parameters - any chance the names of those computers have a hyphen?

Just grasping!

 

[kida]

If your DHCP server is configured to be a DHCP Relay Agent in addition to a DHCP server - take a look at Microsoft knowledge base article - 180557

 

[PlsHlpKat]

It is a problem with the DHCP Server I have put the computers in with a static ip and now I can ping them throughout the WAN. Also as the other machines lease expires the dhcp is not assigning a number and I have to change to a static address. I can not figure out what is wrong with the DHCP.

 

[justcurious]

Kat, can you ping the DHCP server from the workstations? If not, check your network settings. Who else has access to this server? Have you grilled them on what changes they may have made recently?

Maybe now is the time to remove the DHCP scope and rebuild it.

If it was working before and now it's not, think hard about any ( I repeat "ANY" ) changes that may have been made on that server.

While you are at it, go to

http://www.microsoft.com/windowsupdate

and check for updates. Is Service Pack 6a installed? You can check which service pack is installed by running winver in a command window.

Good luck.

Its nice to see someone else has jumped up to the plate and is offering suggestions.