[ipxe-devel] iPXE DHCP timed out with tg3 and Cisco sw. wo "spanning-tree portfast"

Václav Ovsík vaclav.ovsik at i.cz
Mon Oct 15 15:18:32 UTC 2012

On Wed, Oct 10, 2012 at 11:38:48AM +0100, Michael Brown wrote:
> On Wednesday 10 Oct 2012 11:31:35 Václav Ovsík wrote:
> > I just tested a rather new iPXE (cloned git repo) on Dell Latitude D830
> > connected to a port on Cisco switch configured without option
> > "spanning-tree portfast". That is it takes about 30 seconds to transmit
> > packets over it after bringing link up.
> Use an embedded script such as:
>   #!ipxe
>   ifopen net0
>   sleep 30
>   autoboot net0
> Michael

I found a partial solution :).

My motivation to use ipxe.pxe was the functionality in KVM guest with
virtio network interface on Debian Squeeze (current stable).
The image undionly.kpxe is not working with boot ROM supplied with stable
qemu-kvm package.

I tried to build boot ROM for virtio net dev using instructions
at http://ipxe.org/howto/romburning:

    make bin/1af41000.rom

I replaced virtio boot ROM supplied with package qemu-kvm with the built
product above:

    debian:/usr/share/kvm# ls -la 1af41000.rom pxe-virtio.bin*
    -rw-r--r-- 1 root root 65536 Oct 15 08:36 1af41000.rom
    lrwxrwxrwx 1 root root    12 Oct 15 08:37 pxe-virtio.bin -> 1af41000.rom
    -rw-r--r-- 1 root root 32768 Jan 22  2011 pxe-virtio.bin.orig

The combination of this virtio boot ROM and undionly.kpxe is working!
I found some problematic corner cases fortunately not important.
For example Debian Live Squeeze (6.0.x) is working, but Debian Live
Lenny (5.0.x) is not working (kernel panic at the start).

Undionly.kpxe uses BIOS network driver, that doesn't change link state
up/down and thus works on physical computer with problematic tg3 network
interface even connected to Cisco switch without option "spanning-tree

I will use undionly.kpxe.

Kindly Regards

More information about the ipxe-devel mailing list