PXE-E51 "No DHCP or DHCP Proxy Offers received" error

[Forum User_1]

I am unable to get my servers to attach to the RDP server. When they boot, they return a PXE-E51 error saying that No DHCP Server could be found. I know DHCP is available because my laptop can get an address form the same port. I have tried different Proliant G2 servers and am using a Cisco 2900XL switch. Any ideas?

[Jeff Allen_5 · Accepted solution]

This error can occur for a few different reasons.

1) Spanning-Tree is enabled on your Cisco switch and Port-Fast is not enabled on the Host ports. You need to enable Port-Fast on all ports that have PXE clients attached. This disables loop detection on those ports, but it is a common practice on host ports.

2) DHCP is not available or not Authorized (MS AD). In your case, this does not seem to be the case.

3) If multiple NICs are in your PXE client server, ensure you are plugged into the corret NIC. Some NICs tell you when the cable is not connected, others don't.

4) DHCP is on another network segment and there is no DHCP proxy agent or helper address (on the router).

Good Luck

[GHUNIX]

I have 20xBL20p G2 blade servers and managed to install the first server. As soon as I try to create an image the server boots and cannot get a DHCP address, but reset the server and the same nic get a DHCP IP address in Windows 2003. Connected to 2xCisco 2950T switches.

[Lawrence Reynolds]

Thanx a lot...changing all client ports on cisco switch catalyst 5500 to Port-fast resolved my PXE-E51 error immediately..
This info I couldn't easily pick up at both Cisco and Novell web sites..I'm doing PXE boot for Novell Zenworks Imaging purposes..
Once again...THANX...
Lawrence

[Victor_106]

I have the same problem with the same error (error PXE-E51, no dhcp or proxy dhcp offers). I am using an HP 4104gl router swtich with 3 VLANS configured. In conjuction with that switch I am using a GBE2 fibre switch which is the switch for the BL20p Blade servers which have the DHCP and RIS server running on them. I can't seem to get a DCHP address for PXE Nics. I have tested it on a "flat" network and it works. As soon as I go through the switches, I have no luck. any suggestions?

Cheers
Vic

[Duster]

I have the same issue when attempting to receive dhcp to my lan clients when connecting to my blade dhcp using G2e Switches. for some reason the switch doesnt allow the packet trough.

[arquinan]

Thanx a lot.. !!! I have changed all client ports on cisco switch to Port-Fast Enabled, and I resolved my PXE-E51 error immediately..
Once again...Thanks a lot!
Arquinan