PXE boot with Realtek 8111B/C

[birchanger]

Having got FOG running I was over the moon. Our new batch of 25 Tosh laptops went in about as painlessly as possible. So, let's now turn to the 30-odd new Akhter all-in-ones ....

 

I simply cannot get them to PXE boot. They have the same network adaptor as the Toshes, Realtek 8168/8111, but always fail to find a DHCP or DHCPproxy request.

 

I tried a etherboot CD, first on one of our NS Optimum PCs (which have the same adaptor) then on an Akhter. The NS Optimum (which was also refusing to PXE boot) worked fine with this CD - but the Akhter won't.

 

Oddly, the NS Optimum will now PXE boot happily without the CD. It seems that changing the boot device order from LAN/HDD/CD to CD/LAN/HDD was enough to persuade it to work, so that sounds like a timing issue. We are running spanning tree protocol and that is supposed to cause PXE boot problems.

 

But it works fine on the Toshes, and on other, older, machines around the campus. Any ideas? All straws gratefully clutched at.

[SYNACK]

Do you have STP enabled on the switches, if the power saving settings on the card switch it off during a reboot or when the system if off it will mean that an STP lockdown period will occour on the port and will probably still be locked while it is looking for DHCP to PXE boot. This may not affect the other cards if they are set to maintain an active link state even when the computer is off. You could try setting the cards as always active by enableing Wake on Lan in both the bios and the advanced properties of the NIC drivers which should make it remain active. You could also disable STP while imaging, this may not be the cause but is worth looking in to.

[Martin]

A quick thing to try is to press the key when the "DHCP /" propeller starts spinning, wait 30 seconds or so and then press to continue the propeller.

 

That might be enough for STP to settle down and the network port to go "live".

 

mb

[Geoff]

Your supposed to tell STP which ports are edge ports!

[tmcd35]

I've had this on the odd machine before and have found a simple BIOS reset back to factory defaults solved the problem. Don't ask why (I haven't the foggiest) but it seems to do the trick

[CyberNerd]

@ Geoff - does setting the core switches with a lower priority achieve this?

[Geoff]

Yes your core switches should have lower priority.

[SYNACK]

@ Geoff - does setting the core switches with a lower priority achieve this?

 

Nope this step does not configure the edge ports, you need to designate the workstation ports as access ports or portfast or whatever the particular terminology is for your brand of switch. The STP priority just effects the master election process to decide which are the best links to keep active between switches where multiple links are avalible. By electing the core as the master STP will try to create the shortest path to that switch with the avalible links. If this gets messed up it can really mess with your network as STP will enable paths that are the shortest to whichever switch is elected which could be a core switch. If this happens then your network traffic can easily bounce from one end of the network to the other before it makes it to its destination.

[birchanger]

Working! Well, almost. I now have a FOG problem but PXE is working. It was STP stopping me. It's interesting that different machnines with the same network adapter should behave in wildly different ways.

[mac_shinobi]

Working! Well, almost. I now have a FOG problem but PXE is working. It was STP stopping me. It's interesting that different machnines with the same network adapter should behave in wildly different ways.

 

different firmware revision / types on the network cards

[eejit]

A quick thing to try is to press the key when the "DHCP /" propeller starts spinning, wait 30 seconds or so and then press to continue the propeller.

 

That might be enough for STP to settle down and the network port to go "live".

 

mb

 

You have absolutely saved my life

 

PHEW! - shows how invaluable this forum is. Thanks everyone.