Re: xPLMediaNet DHCP - mystery possibly solved

["jamesbresee" <jim.bresee@xxxxxxxxxxxxxx>]

Slick detective work, Tony.=20=20

That also explains the weird behavior. I was scratching my head on=20
that one... I wanted to blame the network switches, but could not=20
figure out what was going on.

I'll see if I can packet sniff the rio asking for its boot.

Jim


--- In ukha_xpl@xxxxxxx, "Tony Tofts" <tony@x> wrote:
> > > When my router serves the address, it can't find the image.
> > Yup, this is consistent with my experience too.
>=20
> Hi all,
>=20
> While changing xplmedianet's dhcp so that it didn't need to serve=20
up any
> boot file etc options to the rio (therefore mimicking the dhcp=20
offer from ms
> dhcp and routers) I think I found the problem
>=20
> It seems if the dhcp packet size is below a certain size the=20
rio/ddar
> totally ignores it. For xplmedianet the solution was simply to=20
pack out the
> minimum packet size it could possibly deliver (i.e. no options)=20
with 32 0's
> on the end (33 if on an odd byte boundry). This then works fine=20
regardless
> of whether I specify any additonal options or not
>=20
> So I'm thinking that maybe some routers are dishing out an offer=20
that's too
> small? If we want to confirm this I'd need someone with the=20
problem to use
> ethereal to capture the offer from the router and send it to me=20
please
> (though this may be difficult unless you have a hub, since I don't=20
think a
> switch - unless it has a snoop port - will pass the offer packet=20
to a
> snooping pc).
>=20
> Strangely I noticed that despite my ms dhcp having the same=20
options for both
> my laptop and the rio it didn't send the router or dns addresses=20
to the rio
> (though this doesn't matter) but did to the pc. I'm sure there=20
must be a
> reason for this, but I can't think of any! Xplmedianet dhcp does=20
send the
> router and dns, and should serve any device requesting an ip.
>=20
> Regards
> Tony