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Re: 'looking up xxxx' forever

On Sat, 3 Apr 2010 14:06:51 -0400 (EDT), Hugo Vanwoerkom wrote:
> I have a dialup modem.
> Pppconfig configured the connection with 'nameservers dynamic'.
> /etc/ppp/resolv.conf always contains:
> nameserver
> nameserver
> although the timestamp on the file changes with each connection:
> -rw-r--r-- 1 root root 53 2010-04-03 11:00 resolv.conf
> Now the problem:
> Several times a day internet communication stops and all that appears on 
> the status bar of iceweasel is 'Looking up xxxx' where xxxx is the site 
> that was being displayed.
> This is only resolved when you take down the ppp0 interface and bring it 
> back up, redialling the ISP.
> And the same nameservers appear in resolv.conf.
> Can anyone explain this behavior? And what to do about it?
> BTW it again happened at 11:00 as you can see.

I'm not surprised that the nameservers don't change.  The file
is rewritten with each connection, thus the changing timestamp.
The nameservers' IP addresses don't change often.  The real
problem, of course, is the loss of connectivity.

There are two possibilities.  ISPs that offer dial-up connectivity
have a limited number of phone lines.  If customers get a busy
signal when they try to dial in, the ISPs get complaints.  And the
ISPs don't like complaints.  So they often have an automatic system
where if all lines are in use and someone tries to dial in, the person
who has been connected the longest gets bumped.  In other words,
the ISP will hang up on you to free the phone line for someone who
wants to dial in.  Of course, when they hang up on people, they get
complaints too.  But not as much as if they can't get in in the
first place.

Another possibility is a short DHCP lease.  When the PPP connection
is established, they lease you an IP address.  And that IP address
has a limited lifetime.  When it expires, you're dead.  Not much
you can do about that except reconnect.   ISPs don't like you to
keep your PPP connection for an extended period of time.  The longer
their customers keep a dial-up connection, the more phone lines
they need to have.  And phone lines (and modems) cost money.  They
want you to get it, get your e-mail, and get out.  They don't want
you connected for a long time.  And so they give you a short DHCP
lease.  And when it expires, you're dead.  (And when you complain,
they'll blame the phone company!)  Look at the logs.  You may be able
to determine the length of your DHCP lease from there.

  .''`.     Stephen Powell    <zlinuxman@wowway.com>
 : :'  :
 `. `'`

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