[cisco-voip] 7940 7960 wont grab ip from dhcp off switch

[Ted Nugent]

Can you provide a switchport config from one of the
phone ports off the 3750 so we can get a better idea
of what we're looking at? Also, can you check if there
is a helper address on whatever is providing routing
for that VLAN?

Another weird problem I ran into was that most newer
servers these days have the ability to trunk on their
NICs which can cause issues for DHCP if the
circumstance are right. I’m having a hard time
thinking of an example right now but I would check if
the sw port for this DHCP server is trunking and if so
disable it or remove the unwanted VLAN from the trunk.


--- James Grace <jgrace at digitelusa.net> wrote:

> What I notice also, is the these phone are getting
> address from the data
> remote dhcp server.  But when you look at the
> setting on the phone it has
> the correct vlan id 
> 
> -----Original Message-----
> From: Jonathan Charles [mailto:jonvoip at gmail.com] 
> Sent: Friday, June 23, 2006 11:05 PM
> To: Ted Nugent
> Cc: Wydra, Jason; James Grace;
> cisco-voip at puck.nether.net
> Subject: Re: [cisco-voip] 7940 7960 wont grab ip
> from dhcp off switch
> 
> Another fun thing is if there is a rogue VLAN
> sitting in the vlan
> database...
> 
> Do a show vlan and see if there are VLANs on the
> switch that don't
> make sense to you... if so, go into VLAN database
> and delete them...
> 
> Also, note the fact that you CANNOT configure a
> 3550, 3560 or 3570 to
> have a voice vlan and configured as a trunk port...
> the voice vlan is
> ignored...
> 
> 
> 
> Jonathan
> 
> On 6/23/06, Ted Nugent <tednugent69 at yahoo.com>
> wrote:
> > Another Problem I've seen that could be
> contributing
> > to this is if you set the access vlan and voice
> vlan
> > the same. (I think it's a bug but have not
> > investigated it).
> > sw acces vlan 4
> > sw voice vlan 4
> > Changing to a different access vlan typically
> fixes
> > this. Also mokeying with the DHCP properties have
> > caused the same problem and simply changing the
> access
> > vlan to to something else and changing it back
> > resolves the problem. You may need to down the sw
> port
> > to get this to take.
> >
> >
> > --- "Wydra, Jason" <jwydra at Burwood.com> wrote:
> >
> > > Are you doing true trunking (encap dot1q) on
> these
> > > ports or are you
> > > doing an access vlan and voice vlan?
> > >
> > > -----Original Message-----
> > > From: cisco-voip-bounces at puck.nether.net
> > > [mailto:cisco-voip-bounces at puck.nether.net] On
> > > Behalf Of Jonathan
> > > Charles
> > > Sent: Friday, June 23, 2006 9:39 PM
> > > To: James Grace
> > > Cc: cisco-voip at puck.nether.net
> > > Subject: Re: [cisco-voip] 7940 7960 wont grab ip
> > > from dhcp off switch
> > >
> > > Do they show up in a 'show cdp neighbors'? If
> not,
> > > you may want to
> > > enable CDP so the phones can see the voice vlan.
> > >
> > >
> > > Jonathan
> > >
> > > On 6/23/06, James Grace <jgrace at digitelusa.net>
> > > wrote:
> > > >
> > > >
> > > >
> > > >
> > > > We have a 3750 with dhcp scope config on it. 
> We
> > > have all type of
> > > phone and
> > > > wireless ap (cisco) that are pulling from this
> > > scope.  But for some
> > > reason
> > > > the 7940s and 7960s are grabing ip from the
> data
> > > remote dhcp server.
> > > The
> > > > switch is not recognizing these phones
> > > >
> > > >
> > > >
> > > > James D. Grace
> > > >
> > > > CCNP CCNA MCSE MCDBA
> > > >
> > > > Sr. System Engineer / Professional Svc.
> > > >
> > > > Digitel Corporation
> > > >
> > > >
> > > >
> _______________________________________________
> > > > cisco-voip mailing list
> > > > cisco-voip at puck.nether.net
> > > >
> > >
> https://puck.nether.net/mailman/listinfo/cisco-voip
> > > >
> > > >
> > > >
> > > _______________________________________________
> > > cisco-voip mailing list
> > > cisco-voip at puck.nether.net
> > >
> https://puck.nether.net/mailman/listinfo/cisco-voip
> > >
> > >
> > > _______________________________________________
> > > cisco-voip mailing list
> > > cisco-voip at puck.nether.net
> > >
> https://puck.nether.net/mailman/listinfo/cisco-voip
> > >
> >
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam?  Yahoo! Mail has the best spam
> protection around
> > http://mail.yahoo.com
> >
> ---
> 
> 
> 
> ---
> 
> 
> 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com