Don't understand DHCP

[mrblonde]

Hello,
A windows NT box (workstation) with service pack 4 went through a power failure two days ago. (The entire building / network actually) Now the message "the DHCP client could not obtain an ip address" is popping up and no computers can see each other on the network nor can anyone access the internet. The NT box is the only one giving me the error message. I know next to nothing about NT. What I can tell you is this: This is the only windows NT machine on the network of 6 computers. The physical connections to the hub seem ok. I have a solid link light on our router. Oh, and I drastically need to resolve this.

Does anyone have a clear idea based on what I've mentioned? Can I get more details for you? Help.

Thanks,
Mat

 

[Invincible]

First I would check it is the DHCP server by assigning 1 machine with a static IP. If this is ok, move onto the DHCP server. If not, check that you can see the other servers (as all servers should be assigned static addresses). If there is still an error I would check network connections.

Basically all the DHCP server does is to allocate ip addresses to the clients based on a range assigned by the administrator. So if you are at this point then :-

1) click on start, programs, administrator tools and DHCP manager - check that the DHCP range is active.

2) Check the event viewer for any errors

Let me know how you get on...Good luck!

 

[WilWolitski]

1) Goto command prompt on NT wkstn.
Type: ipconfig /release
Type: ipconfig /renew

2) View your TCP/IP properties. You might have some static information in there. It sounds like you may have the incorrect subnet mask declared if it can't find a DHCP server

3) The IP address is entered into the registry after every renewal or assignment. When your PC boots up and it cannot find and/or renew its IP address, it will use the information cached in the registry until its time has expired. Hopefully it finds a DHCP server or the DHCP server is fixed before your address expires. This is a good argument for long lease periods.

4) Add NetBEUI protocol (just to maintain your network connection) and remove the TCP/IP protocol. Reboot (cold boot / power cycle) PC and add TCP/IP protocol back in. Maybe driver files or registry got corrupted. When you reinstall the protocol all your past settings will appear again as this information is in the registry.

5) Your infrastructure equipment may have been reset by the power cycle. If there is connecting equipment between the NT wkstn and the DHCP server, you need to ensure that BootP is enabled on the connecting equipment.

Now that should help you!! I [tt]Be a lateral thinker![/tt]

If you always do, what you always did​

​

[tt]Think outside the box[/tt]

You'll always get, what you always got!!​

 

[mrblonde]

Thanks very much!

I will try both suggestions and let you know how things work out.

Thanks again,
Mat

 

[WilWolitski]

1) Goto command prompt on NT wkstn.
Type: ipconfig /release
Type: ipconfig /renew

2) View your TCP/IP properties. You might have some static information in there. It sounds like you may have the incorrect subnet mask declared if it can't find a DHCP server

3) The IP address is entered into the registry after every renewal or assignment. When your PC boots up and it cannot find and/or renew its IP address, it will use the information cached in the registry until its time has expired. Hopefully it finds a DHCP server or the DHCP server is fixed before your address expires. This is a good argument for long lease periods.

4) Add NetBEUI protocol (just to maintain your network connection) and remove the TCP/IP protocol. Reboot (cold boot / power cycle) PC and add TCP/IP protocol back in. Maybe driver files or registry got corrupted. When you reinstall the protocol all your past settings will appear again as this information is in the registry.

5) Your infrastructure equipment may have been reset by the power cycle. If there is connecting equipment between the NT wkstn and the DHCP server, you need to ensure that BootP is enabled on the connecting equipment.

Now that should help you!! I [tt]Be a lateral thinker![/tt]

If you always do, what you always did​

​

[tt]Think outside the box[/tt]

You'll always get, what you always got!!​

 

[majestrate]

WilWolitski,

the only way a SM can be entered is if you choose to enter a static address. if you enter a static address you can't connect to a dhcp server. the only way to make sure that your subnet mask is 255.255.255.255 is to go into the registry. i can't recall the key, but that's the only way you can have a static subnet mask while you're configured to use dhcp.

 

[mrblonde]

I apperciate everyones help. During the power outage the uplink cable from the router to the hub was damaged. Upon replacing it and recylcing (spelling?) the DHCP server was found. My big tip off should have been that no user could access the internet. Thanks for the timely suggestions.

Mat