[cisco-voip] weirdness with DHCP and 7960 phones..

[Simon, Bill]

It's true, the 7960s do not obey the DHCP protocol.
 
If they cannot talk to a DHCP server, they will use whatever previous
address they had.
 
We have complained to Cisco before about this disregard for the protocol and
were told it is "by design".
 
Our solution was to make gigantic DHCP pools for phones so that there is
plenty of address space available and it is unlikely that we will have IP
conflicts.
 

---
Bill Simon - bills at tns.its.psu.edu - (814) 865-2270
http://tns.its.psu.edu/ <http://tns.its.psu.edu/> 



 


  _____  

From: Tim Reimers [mailto:tim.reimers at asheville.k12.nc.us] 
Sent: Monday, April 10, 2006 4:41 PM
To: cisco-voip at puck.nether.net
Subject: [cisco-voip] weirdness with DHCP and 7960 phones..





Hi everyone--- 

We had a weird occurrence in the last few days I thought I'd run past the
group to see what everyone thought... 


A vendor (who shall remain nameless) rebuilt our CCM -- and in the process,
it turns out, failed to reinstall the DHCP server/scope and TFTP options..

All worked fine until we had a power glitch of some sort and the phones
rebooted... 

At that point- well, that's when things get weird.. 

You'd think that NONE of the phones would come back up --- 

but about 20 out of 75 did just that...  with no DHCP server. 

Mine, which was one that did it, is NOT set for static addressing (none
are)... 

Smoehow, it retained it's IP settings, though it took a while to boot... 


my question???  Wassup with that? I thought "no dhcp, no boot', no
NOTHING....for ALL of the phones on that subnet? 

Why did some come up and work and others not? Is there some magic in some of
the boot code? 

(except perhaps a phone with a 169.254.x.x address, trying to find a CCM, a
load ID ,etc..) 

Tim 

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