[ipxe-devel] [Etherboot-discuss] Seconds field of DHCP Discover message not set?

[Michael Brown]

On Tuesday 26 Jul 2011 20:06:17 Kenton Cabiness wrote:
> I have a KVM sytem (RHEL6.1, qemu-0.12.1.2, seabios-0.6.1.2, gpxe-0.9.7,
> virtio bridge interfaces) where we are trying to PXE boot the guest OS.
> 
> It does not appear that the seconds field of the DHCP Discover message
> is being incremented (it is always set to 0).  The DHCP server is not
> connected locally and the DHCP request is not being forwarded to the IP
> helper device (DHCP server) unless the forward delay time is set to 0 on
> the local switch (Omni-switch compares this delay time to the seconds
> field of the DHCP request and only forwards the request if the seconds
> field is >= the delay time).

Upgrade to iPXE (http://ipxe.org) and you'll see the seconds field being 
incremented.

The field does increase monotonically but doesn't represent the actual number 
of seconds elapsed because some bits are (ab)used to convey diagnostic status 
information.  You can read about this at

  http://ipxe.org/err/4c106035

Michael