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R6_5_18, DHCP Server with IP Phone not working

Occasional Visitor

R6_5_18, DHCP Server with IP Phone not working

My DHCP Server IP is

My NCP IP is

I have layer 3 switching done on my 3com 5500 Switch i have configured as below on my port connecting to IP Phone. Data VLAN 2005 & Voice VLAN 2001

interface Ethernet1/0/17

port link-type trunk

undo port trunk permit vlan 1

port trunk permit vlan 2001 2005

port trunk pvid vlan 2005

broadcast-suppression pps 3000

undo jumboframe enable

apply qos-profile default


I have also enabled DHCP-Server relay on Switch


dhcp-server 1 ip


interface Vlan-interface2001

ip address

dhcp-server 1

Any help is highly appreciated.....

This message was edited by FAKHRUDDIN on 5-12-09 @ 7:34 AM
Super Advisor

Re: R6_5_18, DHCP Server with IP Phone not working

Not exactly sure what you mean . Are you saying that the tel will not get a dhcp address ? Can you be a little more detail please ? The NBX tel will boot to dhcp after it attempts to boot to layer 2 then to static ip settings in the phone . If there is a dhcp server online then the dhcp broadcasts sent out via the tel will be answered . I am afraid that thats all the tel does so its up to your dhcp server for the rest .

You can start by visiting our knowledgebase as there are a few docs out there in re to the dhcp scopes with option 184 or visit our data forum for the 5500 as well .

This message was edited by merlin on 5-14-09 @ 6:28 AM
Occasional Visitor

Re: R6_5_18, DHCP Server with IP Phone not working

Assuming you are having trouble with phones gettin addreses from DHCP server...

Had the same problem, I originally had my NBX on VLAN1 and DHCP server on different vlan sitting on my 5500.

After trying just about every form of "port trunk permit", I changed the ip on the NBX to be the same subnet as the DHCP server, and the port config on the 5500 for both devices to ACCESS PORT, PORT ACCESS VLAN(server vlan)

Then on the end point switches, add statement for that VLAN.

Then, be patient. My phones needed to reboot and download NBX image several times at first.

This message was edited by JFisher on 5-18-09 @ 10:11 AM