Ip Phone Registeration Problem

Hi,
I am trying to register ip phone in CCM 4.1.3.
Here is config for switch:

interface FastEthernet0/2
switchport access vlan 3
switchport mode access
switchport voice vlan 2
spanning-tree portfast

VLAN Name Status Ports
----

1 default active Fa0/1, Fa0/3, Fa0/4, Fa0/5
Fa0/6, Fa0/7, Fa0/8, Fa0/9
Fa0/10, Fa0/11, Fa0/12, Fa0/13
Fa0/14, Fa0/15, Fa0/16, Fa0/17
Fa0/18, Fa0/19, Fa0/20, Fa0/21
Fa0/22, Fa0/23, Fa0/24, Gi0/1
Gi0/2
2 VLAN0002 active Fa0/2
3 VLAN0003 active Fa0/2
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
S1_3550#

When I connect this phone to the port which is configured for voice vlan it get stuck at configuring ip message, but when I connect it to any other port which is not configured, it get registered with CCM and works fine !! I am wondering what's wrong with CAT 3550 config ? why it's not working on interface fastethernet 0/2 !
any solution will be appreciated,
thanks

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Comments

mikej412

Sounds like you can't reach the DHCP server from the Voice VLAN.

You either need a DHCP Server on the Voice VLAN or you need to use the ip helper-address command to reach the DHCP Server. Do you have a DHCP scope defined for the Voice VLAN IP Address range?

Since it seems you may have everything in the Native VLAN (DHCP, TFTP, CCM), you may face additional issues after you resolve the DHCP problem -- but that depends on the rest of your network configuration and routing.

nagen

Thanks for reply,
I have defined one DCHP scope on windows 2000 CCM server with tftp option 150 for voice vlan & IP phones. I know I need another subnet for data vlan and PC connected to IP phone but I am wondering on which device I have to configure another DHCP scope, on a router, windows ccm server or on CAT-3550 switch? and inter vlan routing! Can you refer me to any docs from which I can learn configs thoroughly. So far the material I have read talks about everything partially, configure the dhcp scope on ccm, confgure ports on switch, reset IP phones, gives no clue how these devices gonna communicate !!
looking for response,
regards,

mikej412

The closest thing to a "step by step" document is the Cisco Unified Communications IP Telephony Technical Information Site. There are tabs to the major step involved (Prepare and Plan, Design, Implement, Operate), with an outline of the steps, and eventually links to the relevant Cisco Documents.

Another option is the Solution Reference Network Design (SRND) -- the links to the different versions are in the CCVP FAQ. Some of the obvious networking tasks from the CCNA and CCNP aren't even mentioned in that doc -- but you can see in one place the amount of things you potentially need to worry about that specifically impact Voice. In the 4.x version there is a mention of DHCP in the LAN Infrastructure section, and then they provide a couple links and suggest you check out the Gigabit Campus Network Design white paper for more information on campus design.

In the CCVP the concepts and configurations you need to learn are built up step by step as you go thought the Suggested and Recommended Cisco Press books. But all of that is stacked upon your CCNA (and CCNP) knowledge and skills.

As for your DHCP issue -- you can add another DHCP server for the Voice VLAN or add another interface to the existing DHCP server and place that in the Voice VLAN. But the best and simplest solution is to go back to the ip helper-address command from the CCNA.

In a Lab environment you may have your CallManager server plugged into the same switch, and as you have in your working configuration -- the same VLAN with everything else. In real life your CallManager may be in a Server Farm half a world away, so you'd have your network routing and reachability issues to deal with -- along with Security, QoS, and Management issues.

Once you define the scope for your Voice VLAN on your DHCP server, you'll add the ip helper-address command onto the router or layer 3 switch that will route between your VLANS (your default gateway for that scope).

If you're using a Layer 3 switch -- that's where you'd want some of that CCNP knowledge. If you only have a CCNA, then it's time to take a study detour and check out the Switch Configuration Guides (or the CCNP BCMSN books). There is a link in the CCVP FAQ to a basic Switch Configuration Document for Voice -- but it doesn't cover the network and routing issues that the CCVP assumes are already in place.

hedhrts

Another suggestion. If you're familiar with Ethereal, start sniffing traffic. What I typically do is span a port and sniff the phone traffic. This will familiarize you with the boot up communication process (at a detail level) and will be able to steer you in the direction of the possible issue. Keep in mind the first dozen times or so that you use this as a diagnostic tool is going to take forever to figure out (as it did for me), but as you start to know what each piece of the puzzle does troubleshooting gets pretty easy.

What you're looking for at this stage is something I call DORA (DHCP process for getting an IP).

Discover - from client
Offer - from server
Request - from client
Acknowledge - from server

If you sniff the traffic, at this stage you will probably only see a Discover packet, indicating that the broadcast isn't making it to your DHCP server for some reason.

nagen

mikej412 wrote:

The closest thing to a "step by step" document is the Cisco Unified Communications IP Telephony Technical Information Site. There are tabs to the major step involved (Prepare and Plan, Design, Implement, Operate), with an outline of the steps, and eventually links to the relevant Cisco Documents.

Another option is the Solution Reference Network Design (SRND) -- the links to the different versions are in the CCVP FAQ. Some of the obvious networking tasks from the CCNA and CCNP aren't even mentioned in that doc -- but you can see in one place the amount of things you potentially need to worry about that specifically impact Voice. In the 4.x version there is a mention of DHCP in the LAN Infrastructure section, and then they provide a couple links and suggest you check out the Gigabit Campus Network Design white paper for more information on campus design.

In the CCVP the concepts and configurations you need to learn are built up step by step as you go thought the Suggested and Recommended Cisco Press books. But all of that is stacked upon your CCNA (and CCNP) knowledge and skills.

As for your DHCP issue -- you can add another DHCP server for the Voice VLAN or add another interface to the existing DHCP server and place that in the Voice VLAN. But the best and simplest solution is to go back to the ip helper-address command from the CCNA.

In a Lab environment you may have your CallManager server plugged into the same switch, and as you have in your working configuration -- the same VLAN with everything else. In real life your CallManager may be in a Server Farm half a world away, so you'd have your network routing and reachability issues to deal with -- along with Security, QoS, and Management issues.

Once you define the scope for your Voice VLAN on your DHCP server, you'll add the ip helper-address command onto the router or layer 3 switch that will route between your VLANS (your default gateway for that scope).

If you're using a Layer 3 switch -- that's where you'd want some of that CCNP knowledge. If you only have a CCNA, then it's time to take a study detour and check out the Switch Configuration Guides (or the CCNP BCMSN books). There is a link in the CCVP FAQ to a basic Switch Configuration Document for Voice -- but it doesn't cover the network and routing issues that the CCVP assumes are already in place.

Thank you very much for a detailed input, appreciate it. You are right, I need to go back and review some fundamentals. My current understanding of network design and implementation is not enough for CCVP level may be. By the way here is the lab scenario which I am trying to put togather.

Regards,