[gPXE] Dell T300 w/Broadcom chip: gpxe hangs during dhcp

[Peter Scheie]

I've got a Dell T300 that appears to have some sort of Broadcom chip for its 
onboard NIC (Gbit).  I can load gpxe.lkrn via syslinux, which says it's 
initializing the hardware.  But when I then run 'dhcp net0', it spits out the 
MAC address of the NIC, and where there would normally be a series of dots 
marking time while it gets an address from our dhcp server, there appears just a 
single dot and then it just hangs.

So, I tried the other ethernet port (there are two built in to the machine). 
This one gets an address from dhcp, then pulls down the script via http that I 
told it.  This script specifies an initramfs (22MB) and a kernel (1.8MB) to be 
loaded also from the web server.  The initramfs is downloaded, but as it's 
downloading the kernel, it stalls.  I happened to be running this all through a 
linux box acting as a router (because I have worse trouble if gpxe runs on a 
machine connected directly to our network) where I was running tcpdump.  I could 
see the packets being delivered to the gpxe client machine, but when it stalled 
downloading the kernel, there were ARP messages where the router machine was 
asking for the address of the gpxe client machine.

So, any ideas as to
- why gpxe hangs during dhcp for eth0?
- why it would stop communicating with the gateway after ~90 seconds & 23MB?
- what kind of behavior one would expect if a network card/chip is not supported 
by gpxe?
- how to figure out why machines booting gpxe connected directly to our 
corporate network can't get addresses from our dhcp server, and if the address 
is provided by hand, can't download gpxe scripts from an external webserver?

Any suggestions appreciated.  Thanks.

Peter