HP Thin Client - DHCP Issue.

[blakey2]

Hi All,

Mix of HP Thin Clients models TC5520 & TC5530.
30 Thin Clients deployed.
DHCP server is the cisco 1841 router.
100 IPs are avail to be leased out for the 30 TCs (probs when only 50% are used).
Cisco router (DHCP) logs check out fine.
DHCP lease is set to 7 days.

Thin clients periodically come up with the warning

Unable to contact DHCP server. Using cached DHCP credentials

(Or words to that effect).

Problem is that this is coming up frequently, whereas it should only be appearing (at worst) when 50% of the lease time has passed? (otherwise it should not need to contact dhcp server at all??)

If I run an ipconfig /all it shows a valid lease.
If I ipconfig /release then /renew it obtains a new lease no worries.
If I reboot after obtaining a new lease (via release & renew) it still sometimes comes up with the same DHCP error.. (ipconfig /all shows valid lease with 7 days remaining)

Anyone experienced this sort of behavior or can offer any suggestions?

I would think that it was something wrong with the cisco, however my colleague who is a cisco guru believes that there is not a problem with it...

Thanks!

 

[brianinms]

Is the network a flat network? What switches are you using? Is spanning tree portfast enabled on the ports if they are cisco?

 

[blakey2]

Hi Brianinms,

Network segment is flat.


Cisco Router (d.gw)
|
|
HP 2848 Switch
| | | | | | | |
Thin Clients / Printers


All clients connect to a HP managed switch, from memory it is a 2848..

Config is factory default (I believe though I did not set it up myself).

Thoughts..?