PXE Broke...

[mrforgetful]

I suddenly started getting the following error when trying to use PXE. DHCP works fine in Windows.

 

PXE-E51: No DHCP or proxyDHCP

 

Now WINS got disabled last week but was reenabled again to fix a different issue. I don't know if this is related in any way.

 

I've searched all over Google and Experts Exchange to no avail....any ideas?

[Oops_my_bad]

What are you using with PXE?

[contink]

Have you tried restarting the DHCP service as well as running the RIS check?

[mrforgetful]

RIS, or rather WDS in legacy mode in order to load the Ghost Boot Image.

[mrforgetful]

Yeh, I've rebooted all my servers and my Core Switch, checked the Automatic services and they're all started.

[Martin]

From What Are The PXE Error Codes?

 

PXE-E51: No DHCP or proxyDHCP offers were received. The client did not receive any valid DHCP, BOOTP or proxyDHCP offers. To resolve this issue, check each of the following network configuration items:

• DHCP services are not available on the network to which the PXE-enabled NIC is connected.
  
• A DHCP proxy or IP helper address is not configured for the subnet on which the PXE client is connected.
  
• The switch port connected to the PXE NIC is running Spanning Tree Protocol, EtherChannel Protocol, or Port Aggregation Protocol and is thus not activated immediately when a link is detected. This forces the DHCP request from the PXE client to timeout.
  
• DHCP is available on the network, but PXE is not.
  
• The network cable is not attached to the PXE-enabled NIC on the target server.

 

...and just a thought, but does the server have a firewall enabled?

 

mb

[DSapseid]

MY pxe server has 2 network cards on it an i have to disable one if i want to pxe boot for RIS.

[mrforgetful]

DHCP must be enabled as all the computers work fine except for the PXE booting.

Where would I check the DHCP Proxy IP Helper settings?

The switch doesn't have STP enabled, the Core switch does but always has and even if I disable it (which I just tried) it does not fix the problem.

It was enabled fine on Friday morning!

 

No firewall enabled.

 

For some reason Shuttle computers are giving a different error.

 

PXE-T01 File Not Found

PXE-E3B TFTP Error - File Not Found

[boethius]

For some reason Shuttle computers are giving a different error.

 

PXE-T01 File Not Found

PXE-E3B TFTP Error - File Not Found

Hmmm.... doesn't make much sense why you'd see two different responses unless there was a PXEClass there based on the MAC.

 

Given how improbable this is I would say your TFTP server is missing a file that was once there. If you're using RIS this file would be OSchooser\i386\startrom.com. If you're using pxelinux obviously this would be pxelinux.0.

 

I would verify this directory structure and file(s) are present in your TFTP server's root/boot directory.

 

Other than that double-check your DHCP config for the proper boot server hostname/IP address (option 66) and check the boot filename (option 67).

 

Another possibility is that a second TFTP server is running on the same server (assuming your boot server name is as it should be) and using a different TFTP server. Shutdown your main TFTP server and do a netstat for port 69 UDP open to see if you still TFTP open even after it is supposedly shut down.

 

If the DHCP boot server specification and boot filenames/directory structure is there as it should be the only other possibility I can think of is you're getting IPs from a subnet you do not expect and thus possibly getting unexpected PXE responses. Of course you can tell what IP you're getting when you boot via PXE.

 

If all this fails and if you really want to tell what's going on setup Wireshark on your RIS/TFTP server and watch the TFTP traffic when PXE booting. You'll get a very sure and clear idea of what boot file the PXE client is requesting. More importantly if you see no TFTP traffic you definitely know then that something is wrong with your DHCP setup.

 

And if you're dead sure you do not have spanning-tree/etherchannel enabled on your ports the first error might point to an exhaustion of the DHCP IP pool space though if see the error above (PXE-T01 File Not Found) definitely points to DHCP working - unless the working piece is intermittent.

Edited March 4, 2008 by boethius

[mrforgetful]

I've no idea what it was but all iws working again this morning....

 

The last thing I tried last night was recreating the RIS options using Ghost, so this morning I tried again and it all worked.

 

Thanks for all the suggestions.

[adamchapman]

I'm getting the same error... But only on about 10 machines!!!

 

I've successfully imaged 250 using WDS, but these 10 just will not work!!

 

I've tried removing the reservations from DHCP to see if there was an issue there.

PXE-51 no DHCP or proxy DHCP offers were received.

 

any advice - things to check?

[Martin]

The first thing that you must ask is what is different about those 10 machines (compared to the other 250)?

 

Are they identical hardware?

Are they on the same subnet?

Are they connected to a different switch?

etc.

 

Try plugging one of the 10 into a port originally used by one the successfull 250 and try again!

 

mb