[TriLUG] OT: RR Networking Questions

[Greg Brown]

Is setting up a caching DNS server so easy that someone who has already done 
it can throw together a few lines and post it on the list?  (please please 
please)

Greg

On Thursday 11 April 2002 09:22 am, you wrote:
> On Thursday 11 April 2002 09:37 am, you wrote:
> > On Thu, 2002-04-11 at 05:34, M. Mueller wrote:
> > > I have Earthlink DSL.  The DNS servers take a break every now and then.
> > > There are two servers, so I ping one and then the other and compare.  I
> > > don't know a lot about DNS but they seem to throttle every request you
> > > make - even if you "ping 222.111.55.2" for example, the DNS will look
> > > "222.111.555.2" up and you will take a delay.
> >
> > That would be interesting, considering that if you give ping, or
> > any other program an ip address *it doesn't look it up in DNS*!
>
> Sorry for the inaccuracy.  It's been a while since I've had the problem.  I
> notice the problem when I ssh2 out to some ip address.  Using Ethereal, I
> see repeated pokes into the DNS.  If the DNS is being slow, then it appears
> that I cannot connect to the address.  Then I turn off the "nameserver"
> lines in /etc/resolve.conf and try ssh2 again, I don't see the pokes into
> the DNS and away I go to the ip address.  Having the DNS involved with ftp
> or scp between machines on the same subnet drive me bonkers until I figured
> out that I needed to control access to the Earthlink DNS in the
> /etc/resolv.conf.
>
> Earthlink is probably relieved that I am not hitting there DNS with
> unneeded queries.  I wonder what percentage of ISP DNS queries come from
> private LAN activity?
>
> I have a LAN with 6 machines.
>
> - 2 need DNS services for email and surfing.  One is W98.  THe other is
> Mandrake 8.1.  These are allowed to used the DNS always.
> - 1 needs ssh acccess to the world (no DNS required) and occasional
> ftp/surfing (DNS required occasionally).  I manually turn on DNS access
> when I need it by modifying /etc/resolv.conf. Very crude, I think.
> - The remaining 3 need no off-LAN access. /etc/resolv.conf contains "search
> localdomain" only.
>
> THis is admittedly a crude setup, but I avoid hitting the DNS unnecessarily
> and I don't have much administration in the 3 boxes that run exclusively on
> the private LAN.
>
> Any advice on reconfiguring would be most appreciated.  Maybe the machine
> needing occasional DNS access should have a local DNS to provide routing
> answers regarding known addresses (LAN and known WAN addresses)?