DHCP expiry problem with NT Server 4.0

[McLarnon]

All my clients on the network today are losing their IP addresses. As I look at the DHCP manager it shows each client with an expiry time at either some point later today or tomorrow.
My DHCP server is configured to expire addresses every 3 days.
However I didn't think that an address would expire whilst the user was logged on and if it did, it would renew almost immediatley.
I have not been able to restart my servers yet (PDC or BDC) and will do this at the end of the day.

My temporary work around is that I can change clients that lose their address to a static address so that they can carry on working. This is not ideal long term though.

I checked my BDC's event viewer today for the first time in months and it shows that it has been giving the following error since the 15th of June:

Error 213:
Replication of license information failed because the License Logging Service on server \\***** could not be contacted

I have since restarted the License Logging Service on the PDC but this has not made any difference.

Does anyone know as to why this would happen and how I might correct the problem?


Regards

McLarnon

 

[Andyleates]

I think that you can safely ignore the licence logging service messages as they are to do with software licencing and not DHCP leases.

Have you checked your DHCP scope is still active. What happens if you do a release and renew - do you get a new address?

Try increasing your lease time. Remember that a DHCP client will attempt to renew it's lease half way through it's lease period.

Andy

Andy Leates MCSE CCNA MCP+I

 

[McLarnon]

Thanks for replying Andy.

How do you check that the scope is still active? If I go into DHCP manager, click on 'scope' and then 'active leases' it shows all the PC's on the network with a valid address as being highlighted. If I double click on any of these clients it shows that their address is about to expire. All the PC's on the network without an address are slightly greyed out. Some of them expired this morning and haven't renewed. Its looking like all of my clients will be without and address by tomorrow. (Unless I make them static, which I don't want to do).

If I run an ipconfig or winipcfg on any of my clients they show an address completley different from that of my network.

I will increase the lease time but will that start assigning addresses right away to my clients?

Thanks

 

[thebassplayer]

the 1st renewal is at 50% the last is at 87% if no DHCP server is available then the lease will be lost and the address lost. You will need to bring a DHCP server on line or go static

The bassplayer (MCSE, MCT)

 

[wolf2x]

hmmm...it sounds like an odd problem. Can you still connect to the current DHCP server through network neighborhood?

You said that they current IPs of the workstations are different from your network. Are the IPs the self generated kind or a different set of numbers? I'm wondering if you have a rogue DHCP server somewhere on the network.

Just some ideas.

 

[McLarnon]

Thanks for the reply guys.

They were the self generated IPs on my clients. My file server (which also acts as the DHCP server and has done for 3 years now) was still accessable. Just the DHCP that was playing up. I like the idea of a rouge DHCP server but none of my clients have admin access to set that up so it wouldn't be possible.

The problem started when I arrived at the office yesterday morning. Many of my PC's were losing there IP addresses when they expired as the DHCP server was not renewing them. I did not want to restart my server during working hours incase the problem was more complex than I thought and that it would not come back up again.
My call centre would not have been able to process orders during the down time so I had to persevere throughout the day by giving all PC's who lost their address static addresses. Fortunatley the majority where not due to expire until after hours.
At close of play yesterday I was able to restart my servers and after that the DHCP server started to renew all addresses. I have since taken all my statics back up to dhcp clients and everything is running sweet .

Regards

McLarnon