Skip navigation
Cisco Learning Home > Certifications > CCIE Voice (Retired) > Discussions


This Question is Answered 2 Helpful Answers available (2 pts)
2244 Views 5 Replies Latest reply: Nov 17, 2010 4:00 PM by Jeremy RSS

Currently Being Moderated

DHCP Issue

Nov 14, 2010 8:34 PM

Jeremy 13 posts since
Nov 11, 2010

I have a lab which is using a Windows 2000 server with DHCP, CUCM 4.1, DNS, and etc to simulate a network utilizing voice, data, and video.  I can't seem to get my IP Phones or my Computer Clients to get an IP address from the Server.  Here is a picture of the network I am usinglab.jpg


I attached both my HQ Switch & Router Config
In summary I Have assigned Vlan 10 & 20 on HQ Switch and created their interface with an IP address.  I have the ip address-helper command on the interfaces which points to my server that is running DHCP, TFTP, CUCM, and the other services.
My DHCP Scopes are
name: Voice_VLAN10
ip range -
default-router (gateway)
and I have the DNS server
the same is with the Data VLAN which has 10.0.20.x
I have options 066 and 150.  Currently the IP Phones are SIP and I will need to convert them to SCCP.
Now, my PC / laptop will not get an IP address but if I assign one statically (for example), default gateway-
I can ping across my network...
I'm sure its something simple so can somebody please help me.

  • Manny Richardson 1 posts since
    Aug 15, 2009
    Currently Being Moderated
    1. Nov 14, 2010 11:57 PM (in response to Jeremy)
    Re: DHCP Issue



    Can you post a snapshot of the DHCP Scope for the Data VLAN?

  • Paul Stewart  -  CCIE Security, CCSI 6,962 posts since
    Jul 18, 2008
    Currently Being Moderated
    2. Nov 15, 2010 3:17 AM (in response to Jeremy)
    Re: DHCP Issue

    You might also just want to fire up Wireshark on the DHCP server.  That will quickly tell you if the request is making it to the server and let you narrow your focus on the traffic getting to the server, the server itself, or traffic from the server back to the client.

  • Vicente Caballero 1 posts since
    Jul 14, 2010
    Currently Being Moderated
    4. Nov 17, 2010 3:22 PM (in response to Jeremy)
    Re: DHCP Issue


    it wold be helpful to configure again the dhcp scope on the router and issue a debgu command, here is an exaple:

    Router# debug ip dhcp server events

    Router# debug ip dhcp server packets

    DHCPD:DHCPDISCOVER received from client 0b07.1134.a029 through relay

    DHCPD:assigned IP address to client 0b07.1134.a029.

    DHCPD:Sending DHCPOFFER to client 0b07.1134.a029 (

    DHCPD:unicasting BOOTREPLY for client 0b07.1134.a029 to relay

    DHCPD:DHCPREQUEST received from client 0b07.1134.a029.

    DHCPD:Sending DHCPACK to client 0b07.1134.a029 (

    DHCPD:unicasting BOOTREPLY for client 0b07.1134.a029 to relay

    DHCPD:checking for expired leases.
    as you can see it is very straight forward to fin the error.
    On the other hand, even thoug i don't think it is affecting, the "ip helper-address" command is only necessary on the VLAN 10 and 20.


More Like This

  • Retrieving data ...

Bookmarked By (0)