[geeks] Common IP lease?

Greg A. Woods woods at weird.com
Mon Apr 1 13:18:44 CST 2002


[ On Monday, April 1, 2002 at 02:20:55 (-0600), Geek wrote: ]
> Subject: [geeks] Common IP lease?
>
> Ok, my ISP, Shaw Cablesystems, uses DHCP, though it rarely, if ever,
> changes. I was wondering if this one thing I have encountered is
> unusual among ISP's or whether this is a common thing. The IP lease I
> get is for 2 days.

That's certainly very common for both Shaw and Rogers!  ;-)

It's pretty common for the smaller cable ISPs I deal with directly too.

> I have configured my Win 2K box so it can stay up
> much longer, and if I were using Linux/BSD/Solaris or anything else
> it would be even longer.

Hmmm.... but what does that have to do with the DHCP lease?  The uptime
of your system, the DHCP lease expire time, and the "stability" of the
IP address you're assigned, are all pretty much unrelated to each other.

(though of course the shorter the lease the more frequently the ISP can
arrange to assign you a different address if they so please :-)

> When I try to renew the IP so that it does
> not expire I get "DHCP Server Unreachable".

Hmmm.... let me guess:  You've been given some kind of proprietary
modem, such as maybe a Terayon model or something simiar (though
probably not LanCity, and definitely not likely a DOCSIS v1.1 compatible
modem).

I've a sneaking suspicion (based on industry rumours I've heard) that
Shaw might have tried to use NT for their DHCP servers too, which won't
be helping any for sure!

The @Home DHCP servers used by Shaw (and Rogers) customers before
@Home's demise were, if I understand correctly, Solaris boxes.  However
since the switch over to running their own networks (again), they've
each gone their own way.  I can't tell what the Rogers DHCP server is
running -- it's apparently quite well firewalled now, both from the real
world and from the cable side....

> When the lease expires
> the only way to get back online is by reboot.

That's just M$-windoze stupidity.

> So I ask you, a list of
> users who I am sure are more knowledgeable of ISP standards and
> practices then I am, is a this a common practice?

It's certainly not uncommon.

Have you had your cable modem since before Jan 1.  I.e. since before the
switch over from @Home?

> I mean this is
> supposed to be always on access, but I can't stay on for more then 48
> hours at a time without reboot. I think this is more then a little
> pathetic for a service like this. Thanks in advance. 

The best I can suggest is to run a real OS.....  :-)

NetBSD gateway, running the integrated ISC dhclient, stays up pretty
much forever if you don't count "scheduled downtime".  I do have to
restart dhclient when the IP address does actually change, but that's
because of a bug in the particular version of the ISC DHCP software
integrated into the particular version of NetBSD I'm using.  From what I
understand that bug has been fixed in subsequent IHC DHCP releases.

(either that or it's because my default route does not point over the
cable modem....  :-)

-- 
								Greg A. Woods

+1 416 218-0098;  <gwoods at acm.org>;  <g.a.woods at ieee.org>;  <woods at robohack.ca>
Planix, Inc. <woods at planix.com>; VE3TCP; Secrets of the Weird <woods at weird.com>



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