Re: dchp server question

[Jonathan Q <jq@example.com>]

Jean-Christian Imbeault (jean_christian@example.com) wrote:

> [Jonathan Q <jq@example.com>] wrote

> >GOL's nameservers are not authoritative for gol.com, yet

Oops, I should have said jc.com there.  They are, of course
authoritative for gol.com :-)


> I think I understand, but just for my personal education what is an 
> "authoritative nameserver"?

That's a nameserver that has the zone file for that domain
and gives authoritative answers for it.  When you do a whois
lookup, the nameservers there should be authoritative (although
unethical individuals can list any old nameserver there, and some
of them do it; spammers sometimes do it as an obfuscation measure),
but you can make sure by doing a dig or nslookup at that nameserver
directly.  If it gives you a non-authortative answer (which 
203.216.70.70 will if you ask it about jc.com), then you know
it's not authoritative.

> Very unintentional ... I didn't think that the domain I gave dhcpd was 
> actually used for anything .... I'll take it out right now.

A whois lookup is your friend on things like this.  But it's best
to not use domains that you don't own even then, since a domain
that isn't registered today might be tomorrow.

> Bogons gone, said erro gone too! What a coincidence. But now I get:
> 
> 192.168.0.2: resolver failed.
> 
> I guess this is a reference to being unable to resolve a DNS query for the 
> 192.168.0.2 ip? Is this important? Do I need to install some sort of local 
> DNS server to fix this? (or maybe just a local DNS file?)

Don't know if it's important or not.  As long as your dhcp is working
and you can get to the Internet from those machines, it's probably not
important.  If you can tell dhcpd to not do a lookup, that's probably
the simplest way.  Or you could set up a local nameserver
if you want.  

Another thing you want to be sure to have is (to put this in
Cisco terms) an access list that prevents any of those 192.168
addresses from getting out of your network and onto the Internet.
Of course, the DSL router should have those filters as well, and
GOL routers certainly have access lists for that purpose as well,
but anytime you're using non-routable IP addresses on a network connected
to the Internet, it's considered best practice to filter those 
addressses on your outbound interface, even if you know that there
are other routers upstream that are also filtering them.

Glad I could be of help.  I think everybody must be on vacation.
I will be too, starting tomorrow :-)

Cheers,

Jonathan