[TriLUG] OT: RR Networking Question

[M. Mueller]

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)?

-- 
Michael Mueller
Signalnetware, Inc.
www.signalnetware.com
919.621.6090