[PACUG] RE: [cisco-voip] Ip phone are not able to pull addressfrom new DHCPserver

Wes Sisk wsisk at cisco.com
Thu Mar 24 15:16:18 EST 2005


When the DHCP discover arrives at the server, is the RELAY agent set in 
the header?  This will confirm
1. the phone sent the DHCP DISCOVER tagged with the voice vlan 
(sometimes it doesn't, this is a phone bug)
2. the ip-helper address is correctly configured on the router.

/Wes

Rossella Mariotti-Jones wrote:

>The DHCP discover message gets to the server, the DHCP offer gets back,
>I can see it going through the gateway, but no DHCP request originates
>from the phone.
>
>Rossella Mariotti-Jones
>Network Analyst, CCNA
>Chemeketa Community College / IT
>T 503 589 7775
>F 503 399 4898
>E rossella at chemeketa.edu
>www.chemeketa.edu
>
>-----Original Message-----
>From: Marc Hering [mailto:mhering at reval.com] 
>Sent: Thursday, March 24, 2005 11:21 AM
>To: Rossella Mariotti-Jones; cisco-voip at puck.nether.net
>Subject: RE: [PACUG] RE: [cisco-voip] Ip phone are not able to pull
>addressfrom new DHCPserver
>
>Is the DHCP request getting to the DHCP server???  I'd Use M$'s network
>monitor at this point to watch the DHCP Request come in and see what it
>responds with and where the repsonse is going...Could be the ip
>helper-address is messed... 
>
>-----Original Message-----
>From: cisco-voip-bounces at puck.nether.net
>[mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Rossella
>Mariotti-Jones
>Sent: Thursday, March 24, 2005 2:07 PM
>To: cisco-voip at puck.nether.net
>Subject: RE: [PACUG] RE: [cisco-voip] Ip phone are not able to pull
>addressfrom new DHCPserver
>
>After capturing some packets we found that the DHCP offer gets passed to
>the phone vlan through the gateway but there is no DHCP request going
>back to the gateway from the phone. Our set up is very similar to what's
>described here:
>http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a
>0080114aee.shtml#how except the interface on the 6500 to which the
>phone/pc connects to is not set up as trunk as described in the article,
>our interface is set up this way:
>interface FastEthernet8/31
>no ip address
> switchport
> switchport access vlan 600
> switchport voice vlan 200
>However, it's always worked perfectly up until now.
>What would not allow the ip phone to send out a DHCP request?
>
>Rossella Mariotti-Jones
>Network Analyst, CCNA
>Chemeketa Community College / IT
>T 503 589 7775
>F 503 399 4898
>E rossella at chemeketa.edu
>www.chemeketa.edu
>
>-----Original Message-----
>From: Wes Sisk [mailto:wsisk at cisco.com]
>Sent: Thursday, March 24, 2005 7:30 AM
>To: Portland Area Cisco Users Group; Rossella Mariotti-Jones
>Subject: Re: [PACUG] RE: [cisco-voip] Ip phone are not able to pull
>address from new DHCPserver
>
>I saw this once before when the switchport for the DHCP server was
>configured to be a trunk port.
>The DHCP server saw every DHCP DISCOVER message twice. Once on the
>native voice vlan, and once with the DHCP relay agent correctly set by
>the router in the DHCP server. Because the discovers were slightly
>staggered, the DHCP server would NAK that subsequent DHCP REQUEST.
>
>Can you get a sniffer trace at the DHCP server or a sniffer trace of all
>
>traffic in/out of the phone?
>
>/Wes
>
>Rossella Mariotti-Jones wrote:
>
>  
>
>>The TFTP server is running, nothing has changed except for the DHCP 
>>server itself. The ip phone shows up in the list of leases on the DHCP
>>    
>>
>
>  
>
>>server which means that the DHCP has passed an IP address to it but 
>>the phone is stuck on 'configuring IP' and won't go further, I'm 
>>wondering at this point if there's something I need to change in CM?
>>
>>//Rossella Mariotti-Jones//
>>
>>//Network Analyst, CCNA//
>>
>>**/Chemeketa/****/ Community College/****/ / IT/**
>>
>>//T 503 589 7775//
>>
>>//F 503 399 4898//
>>
>>//E ////rossella at chemeketa.edu// <mailto:rossella at chemeketa.edu>
>>
>>//www.chemeketa.edu//
>>
>>
>>    
>>
>------------------------------------------------------------------------
>  
>
>>*From:* Voll, Scott [mailto:Scott.Voll at wesd.org]
>>*Sent:* Tuesday, March 22, 2005 10:54 AM
>>*To:* Rossella Mariotti-Jones
>>*Cc:* cisco-voip at puck.nether.net
>>*Subject:* RE: [cisco-voip] Ip phone are not able to pull address from
>>    
>>
>
>  
>
>>new DHCPserver
>>
>>make sure the tftp server is running on the same ip your giving out in
>>    
>>
>
>  
>
>>the 150 scope.
>>
>>
>>    
>>
>------------------------------------------------------------------------
>  
>
>>*From:* Rossella Mariotti-Jones [mailto:rossella at chemeketa.edu]
>>*Sent:* Tue 3/22/2005 10:37 AM
>>*To:* Voll, Scott
>>*Cc:* cisco-voip at puck.nether.net
>>*Subject:* RE: [cisco-voip] Ip phone are not able to pull address from
>>    
>>
>
>  
>
>>new DHCPserver
>>
>>Hey Scott!, yes we did, we also did a factory reset... thanks for 
>>checking though ;-)
>>
>>//Rossella Mariotti-Jones//
>>
>>//Network Analyst, CCNA//
>>
>>**/Chemeketa/****/ Community College/****/ / IT/**
>>
>>//T 503 589 7775//
>>
>>//F 503 399 4898//
>>
>>//E ////rossella at chemeketa.edu// <mailto:rossella at chemeketa.edu>
>>
>>//www.chemeketa.edu//
>>
>>
>>    
>>
>------------------------------------------------------------------------
>  
>
>>*From:* Voll, Scott [mailto:Scott.Voll at wesd.org]
>>*Sent:* Tuesday, March 22, 2005 10:31 AM
>>*To:* Rossella Mariotti-Jones; cisco-voip at puck.nether.net
>>*Subject:* RE: [cisco-voip] Ip phone are not able to pull address from
>>    
>>
>
>  
>
>>new DHCPserver
>>
>>have you unplugged the phone and plugged it back in yet?
>>
>>
>>    
>>
>------------------------------------------------------------------------
>  
>
>>*From:* cisco-voip-bounces at puck.nether.net on behalf of Rossella 
>>Mariotti-Jones
>>*Sent:* Tue 3/22/2005 10:23 AM
>>*To:* cisco-voip at puck.nether.net
>>*Subject:* [cisco-voip] Ip phone are not able to pull address from new
>>    
>>
>
>  
>
>>DHCPserver
>>
>>I forgot to say that the DHCP server does show that the phone has 
>>acquired an address.
>>
>>//Rossella Mariotti-Jones//
>>
>>//Network Analyst, CCNA//
>>
>>**/Chemeketa/****/ Community College/****/ / IT/**
>>
>>//T 503 589 7775//
>>
>>//F 503 399 4898//
>>
>>//E ////rossella at chemeketa.edu// <mailto:rossella at chemeketa.edu>
>>
>>//www.chemeketa.edu//
>>
>>-----------------------------------------------------------------------
>>    
>>
>-
>  
>
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>>PACUG mailing list
>>PACUG at tire.patch.com
>>http://tire.patch.com/mailman/listinfo/pacug
>> 
>>
>>    
>>
>
>
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