[syslinux] PXELINUX 4.10-pre17 and newer Dell OptiPlex/Latitude/Precision

[Gene Cumm]

Shantanu, let's continue here.

You first noticed this on a Dell OptiPlex 755.  I think it covers all Dell
OptiPlex/Latitude/Precision models that are PCIe based with Intel LoM (LAN
on motherboard) utilizing the BIOS PXE OROM, based on the similarity of
these systems.  The symptoms are that PXELINUX requests pxelinux.cfg/<UUID>
by TFTP (but it might not strictly be a TFTP issue) when not on the same
subnet, responses are sent back but PXELINUX doesn't receive these
packets.  PXELINUX also doesn't respond to ICMP echo (ping) or ARP requests
but repeatedly sends ARP requests for the gateway, as if it doesn't receive
the replies.  When on the same subnet, Shantanu reports that it seems to
hang on the request of pxelinux.cfg/default.

I also tried 4.10-pre13 to no avail.

This makes me think it goes deaf/ignorant for some reason.  My next tests
are TFTP on same subnet, HTTP on same and different subnets then a debug
build with the serial port.

--
-Gene