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Re: [OCLUG-Tech] need help solving an issue with my network

I'm sorry, I forgot to wish everyone a happy new year, so Happy New
Year to everyone on the list.


On Sun, Jan 1, 2012 at 12:09 PM, Brenda J. Butler <bjb [ at ] sourcerer [ dot ] ca> wrote:
> Do the machines with DNS problems get their IP addresses via
> DHCP?  Do they get their nameserver info from DHCP as well?

Yes, and Yes.

> If so, is DHCP still working?  DHCP-assigned addesses have
> to be renewed via leases.
> Maybe the kids machines/phones DHCP leases expired before
> the other leases ...

Yes (I think).  I have to confess I don't really know how to check if
the DHCP server is working.  What I do know is that each machine has
the ip address it is supposed to have and each machine visible on the
ip network (is pingable and can ping other machines).  While I use
DHCP, the server has address reservations for each machine on the
network so each machine is given the same ip address regardless of the
length of the lease or the other machines on the network.  The address
reservations are used so that I,  Big Brother, can know which sites
each kid is visiting.

The leases are set to expire in 24hrs. and I've checked the dns
servers on the kids (Windows XP) machines with ipconfig /all.  Both
machines list the same servers that the dhcp server is serving.

> Have you done an upgrade lately?  Changes to the firewall?

The only change that was made was to allow the android-based phone
onto the network (I use mac filtering in addition to the wireless
security).  I was allowed access to the router and was able to access
web sites but at some point has lost that access.

The kids' machines had stopped working before the changes to allow
access by the android-based phone.

There have been no other changes to the network/firewall.  In that
past, I did discover that an older netgear router failed after I added
a new rule to its firewall.  I was annoyed by this because the netgear
router failed silently - there was no indication that I exceeded the
number of rules I was allowed and there was no indication in the
manuals that there was a limit.  As i recall the limit was something
small like 7!

> You can use the dig command to direct DNS queries to a particular
> DNS server:
>    dig @server.to.query domain.to.ask.about
>    dig @server.to.query domain.to.ask.about NS

dig isn't available on the kids machines.  nslookup (the older
command) does have a 'set all' command that lists the servers that the
dns uses.  I believe the syntax on nslookup is:

nslookup domanin.to.ask.about server.to.query

This command is what showed the dns querries are timing out.


thanks for responding Brenda.  The kids are ashamed that their dad
can't fix their computer problems ;-).  I appreciate the help.