When DNS over DHCP breaks?

Duane Morin dmorin at morinfamily.com
Wed Feb 12 15:59:28 EST 2003


At 03:26 PM 2/12/2003 -0500, Jerry Feldman wrote:
>Duane,
>Sounds like either your router is not working or your ISP's DHCP server
>is broken.
>Is your staticly connected box connected directly to the cable modem (or
>DSL) or is it connected directly to the router?

Ok, here's the scoop.  I've got A Linksys firewall/router that has cable 
modem line going in, 4 regular ports, and wireless.  I have a Mandrake 
linux box connected straight to the router (i.e. not wireless) which is 
static IP and working fine. It is receiving SMTP traffic for me.

I have a linux laptop which is wireless, static IP and working fine.

The problem is the XP box, wireless, DHCP. I tried making it static but it 
didn't seem to have any effect.  Note that when I'm talking DHCP I'm 
talking about my own internal network -- the only IP assigned by my ISP is 
assigned to my router, and as far as I know that's not causing me a problem 
(since the other machines work ok).

The most likely culprit, though I dont understand why : today when I 
rebooted the machine (before problems began, if I recall), it came up and 
told me "found new hardware" despite the fact that I haven't connected 
anything.  The hardware only identified itself as "win driver virtual 
device".  The only thing I could think is that I had downloaded an upgrade 
to my MP3 player software and not rebooted, so maybe that was it.  I 
removed that software, but still this hardware thing persisted.  I tried to 
OK it just to follow through the procedure and see if I could identify what 
it was, but Windows told me it couldn't find any drivers.  Assuming that I 
was now in a case where I had removed the drivers it thought it wanted, I 
clicked the box that said dont remind me of this hardware anymore.

I'm wondering now if that somehow has screwed up my net 
connection.  Everything is reading normal, IPconfig gives me whatever 
address I tell it (be it static or dynamic), my wireless signal is strong, 
and so on.  I just can't get outside my router from this one machine.

After I send this I will reboot the machine in safe mode, then fire it up 
again and see if I can get it to better understand the purpose of that 
mysterious "win driver".

Duane



>Assuming your cable or DSL connection and equipment is working
>correctly:
>I would take the following steps:
>1. Bypass ther router and connect your DHCP client machine directly to
>the DSL or cable modem. If everything works, we can assume the problem
>is at the router end. If not, the problem is with your cable/DSL
>equipment or your ISP.
>2. reboot the router, reconnect it and check all the settings. You
>should be able to find the assigned IP address and the appropriate DNS
>server.
>3. If the router seems to be the problem, reset the router to factory
>settings and re-input the various settings. Possibly even reflash the
>firmware.
>4. If things still don't work and you are sure it is the router, if you
>live in a high rise, take it up to the roof and tell it to make like a
>bird. If you don't have easy access to a high rise, just drop it out of
>your car on 128.
>
>
>On Wed, 12 Feb 2003 14:38:29 -0500
>Duane Morin <dmorin at morinfamily.com> wrote:
>
> > This morning one of my machines, which is connected via DHCP to my
> > router, apparently stopped doing DNS properly.  I am guessing this
> > because all of the operations from that machine that connect directly
> > to an IP, i.e. my mail program, work fine, but attempt to go to a web
> > site by name fails.
> >
> > My statically configured box which has /etc/resolv.conf with 3
> > nameservers in it continues to work fine (although I have not rebooted
> > it lately).  Anybody got suggestions on what might be going wrong with
> > this machine, and where I can start looking?  I tried telling it the
> > DNS servers (while keeping it on DHCP) but that failed.
> >
> > Ok, wait, tried a few things and it's weirder than I thought.  Any
> > attempt to ping addresses by number outside of my own domain fail as
> > well, which suggests I don't have a connection to the outside.  I do
> > have a connection to the inside of my network, though, so I know that
> > I have wireless at least.  So I guess what's happening is that my
> > router has decided to stop allowing this machine to connect to the
> > outside world?  Why would that be?  I have confirmed that my other
> > machine can connect to outside machines both by name and number, and
> > look things up in dns.
> >
> > This is an XP machine, in case that matters.  The static box that's
> > working is Linux (of course).
> >
> > Duane
> >
> > _______________________________________________
> > Discuss mailing list
> > Discuss at blu.org
> > http://www.blu.org/mailman/listinfo/discuss
> >




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