[clue-tech] Network Woes

[Jim Ockers]

Hi Todd,

Todd A. Gibson wrote:
> 
> On Mon, Jun 19, 2006 at 04:52:30PM -0600, Jim Ockers wrote:
> > Todd,
> > 
> > > Setup: Everything in the house is connected to a switch.  A DSL modem
> > > and a server have fixed LAN IP addresses.  The other computers receive
> > > DHCP services from the server (DHCP server services are turned off on
> > > the DSL modem).
> > > 
> > > Symptoms:
> > > I lose the ability to make new connections through the DSL modem
> > > (either into or out of my server).  New connections include Web
> > > queries, ssh, telnet, ftp, etc.  Also during this time some LAN
> > > traffic is hamstrung.
> > > 
> > > Examples:
> > > local_one$ ping local_two #works OK
> > > local_one$ ssh local_two # 15-30 second delay before prompted for password
> > > local_one$ ssh 192.168.1.246 # prompted for password immediately
> > 
> > Please run ssh inside of strace and see what system call is waiting
> > for a return code.
> 
> When DSL is down, ssh it polls 192.168.1.2 which is the server running DNS.  Then it
> polls the secondary DNSs which are on the other side of the DSL modem.
> After a few more polls it looks like it connects with my local DNS
> and continues on.  
> 
> When DSL is up and running, it immediately connects with the local
> server and is off and running.  I don't think any of this addresses
> my DSL woes, but does it indicate an obvious misconfiguration of my
> DNS server?

I would say that the DNS server running on 192.168.1.2 is failing to
properly respond to requests while the DSL is down.

You could test this by using dig to generate queries against 192.168.1.2 
manually while the DSL is down.

Hope this helps,
Jim

-- 
Jim Ockers, P.Eng. (ockers at ockers.net)
Contact info: please see http://www.ockers.net/