[PLUG] Troubleshooting DHCP...

[drew wymore]

On Sun, Dec 27, 2009 at 10:55 PM, Michael Robinson <plug_1 at robinson-west.com
> wrote:

> On Sun, 2009-12-27 at 21:13 -0800, Daniel Johnson wrote:
> > > The other diskless machine on another nic off of the same server, dodo,
> > > boots just fine by the way.  Is something obviously wrong in my dhcp
> > > config file or am I looking at a problem with the switch?  DHCP worked
> > > when I was using a 10BaseT hub which makes me wonder if the line can't
> > > support 100baseTX.
> >
> > It could be a problem with autoconfiguring the speed, and duplex of
> > the connection.  I've had two switches decide on different modes, and
> > thus get a broken network.  When one side is a dumb 10 megabit hub it
> > doesn't try to negotiate, so you never have to worry about that
> > problem.  If you can force it into different modes try that.
>
> I forced the server to half duplex using ethtool, but I can't force the
> client to go to half duplex.  Put the 10Mbit dumb hub back in, dhcp
> worked like a charm and the machine network booted no problem.  I wonder
> if being a switch it was blocking the dhcp replies?  I should in theory
> be able to pull the hub and replace it with a crossover coupler.  I'm
> starting to think that the switch I was trying to use is bad or maybe
> I need a 100 megabit per second hub instead.  Thing is, I use another
> DSS5+ switch with a linksys wireless WAP11 plugged into it that
> configures via dhcp no problem.  I'm not sure what the issue is here.
>
> Just to double check, 190' is within the range limitations for
> 100BaseTX, right?
>
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Yes, up to 300' in the accepted range. I don't think Daniel nor was I
referring to the client/server but the switch itself. Most switches are auto
sensing the link speed and do just fine, without knowing what kind of switch
it is and what capabilities it has, it's hard to say what count be causing
the problem. Could be VLAN's, could be auto sense not working, could be an
ACL .. but without knowing what hardware it is, hard to say.

Drew-