Hi Simon,

I responded to your post on the forums; http://forums.networkinfrastructure.info/nortel-ip-telephony/ip-phone-dhcp-problem/

Let’s keep the discussion on the forums and I’ll try to help you along.

Cheers!

We are running Nortel CS1KE with Succession 5 and have mixed phones of 2004P2, 1140 and 1150.

We are using full DHCP to configure all of the phones and this has been working fine for several months. The last couple of days however, the vast majority of phones are dropping the connection and displaying ‘DHCP Server unreachable’

We can ping the phone from the DHCP server fine. Rebooting the phones does not make any difference, nor does deleting the lease from DHCP server or rebooting the DHCP server. After an hour or so the phones come back of their own accord??

I have never seen anything like this, and it does not effect all of the phones.

Has anyone experienced this, or any ideas on a possible cause/solution?

Many thanks, Simon

I completely agree with you that anything to minimize the human interaction with deployment is a must. The difficulty comes with the end users IT department. I am the voice guy, he is the data guy, it’s his network, his policies his job on the line if he upsets his manager.. the voice guy has to move. The voice guy isnt allowed to touch or interfere with the customers network configurations, but is expected to get the phone working regardless… and at no additional capital cost. This customer, as with all public school environments, wants the port locked down. Sticky MAC and 2 devices must stay, else the Nortel solution will be thrown away. At the same time, the Cisco educated IT people want the phones to deploy and work like Cisco… (lets give them analog POTS then) :).
with the port device count at 2 and sticky MAC on, there is no way this side of armagedon, that any Nortel IP set will register with a full DHCP and VLAN = Auto setting. The set being sent to the Voice VLAN (191) will not function, the port already has two devices registering. Sticky MAC makes it doubly worse, because the MAC address of the set is already discovered and associated with the access VLAN. LLDP doesnt make it work ither, as long as the port settings are as stated. Compromise has to occure, two extra key presses on initail set deployment, to manually set the VLAN tag ID, or disable sticky MAC and increase the port device count to 3. I have had access to a lot of interoperability documents and this topic is not covered. I doubt Cisco will ever approuch it as the attitude there is “you fit in with us”. Customers cant afford to pay for a study trial. So the fact we have any (Nortel) documents at all is a bonus. Just another big vendor running roughshod over customer choices…
There is as yet, no such thing as a zero touch IP set deployment… thats why students get to make a few bucks on big deployments.
This customers issues are for the future. i.e. when and if the set user moves to another physical location in a different logical subnet and wants to keep the phone and the number.
The reason the post ended up here? Because unfortunately there are not enough event error strings available to split the symptoms into smaller groupings when a set deployment fails. DHCP parse error.. DHCP server unreachable… how may causes? This is just another one and the only current solution choice availabale given the scenario.

By the way.. I wish all blogs and forums were as informative as yours.. keep up the very good work

Hi Chris,

This might be acceptable for a handful of phones but when you start approaching the hundreds or thousands of phones, hard coding the phones for a specific VLAN ID is sure to be problematic down the road. Have you reviewed the configuration of the Cisco 3750E with LLDP?

As a side note the majority of people with “DHCP Parse Error” have both DHCP options configured with-in the same scope. Only option 191 is required in the data VLAN scope while option 128 is required in the voice VLAN scope.

Cheers!

Telephone Terminal Type: 2002P2
Firmware: 0604DBL

Any other suggestions to get this going?

Success!, this is what I did:

1. Changed option type from string to encapsulated.
2. Configured option 128 and 191 on both vlan´s scopes (Data and Voice).

option 128: “Nortel-i2004-A,10.0.0.5:4100,1,5;10.0.0.5:4100,1,5.”
option 191: “VLAN-A:2.”

Notes:
—–
-both options without quote marks!
-be sure to remove “00” code at beginning.
-use mnemonic “VLAN-A”, others seems not to work.

3. I have configured switch port to “untag PVID only” (PVID pointing to Data vlan) to permit me connect later a pc on that port without problems.

thks and rgds,

Very interesting… how do you have the phone configured and what version of firmware is it running?

If you have the opportunity a sniffer/packet trace would really help you… or if you can run your DHCP server in debug mode that will probably help too. Are you using DHCP option 191 to return the Voice VLAN to the phones?

Cheers!

Thks Michael,

Don´t worry about “aaa…” and “ppp…” information, I just put it to not use the real ones. It is weird, with full dhcp selected at phone keep receiving parse error, with partial dhcp and manually configured call server ip, phone connects right. I quoted string with single, double and none marks without success. Firmware version is 0625C4l.
I don´t think it is something related with vlans nor dhcp-relay because partial dhcp is working. Seems like string is not been sent by dhcp server or phone don´t understand it.
I will try to capture some frames to see what´s going on there…

Hi Oscar,

Yes it will work with Microsoft’s DHCP server. The string you described above… “Nortel-i2004-A,aaa.aaa.aaa.aaa:pppp,1,5;0.0.0.0:0,0,0.” I hope you realize that you need the IP address of your Call Server node in place of ‘aaa.aaa.aaa.aaa’ and the port you are using in place of ‘pppp’. Here’s an example that I use in my network;

"Nortel-i2004-A,10.1.240.40:4100,1,10;10.1.240.40:4100,1,10."

You’ll note that I use Alcatel-Lucent’s VitalQIP so I need to enclose the entire option within quotation marks within VitalQIP.

Good Luck!

“The Microsoft-based DHCP server usually allocates 312 bytes for DHCP options. That is more than enough for most option configurations. Some other DHCP servers and clients support option overlay, in which unused space in other standard DHCP message header fields within the DHCP packet can be overlaid to store and carry additional options. Microsoft DHCP service does not support this feature. If you attempt to use more than 312 bytes, some option settings will be lost. In that case, you should delete any unused or low-priority options”…took from “http://technet.microsoft.com/en-us/library/cc958929.aspx”

Have you ever tried with MS DHCP server?, thks.

-Oscar

Thanks for your support!

I think we should have bought 1120E/1140E instead of 1110 series. Anyways, thanks again for your advice.

Micheal! , there is no rating for your Blog service. If it was a rating, I would like to give it 5 out of 5. Good work! ;)

– Sajid

In terms of the “DHCP Parse Error”, advice is to:
– check the configuration of the DHCP server
– ensure that the latest firmware is loaded on the IP Phone. Phones shipped from the factory may NOT have the most recent version so the first step should always be to upgrade them.

I’m not 100% sure that there is a SIP firmware available for that model.

Have a look at the comments in this post and you’ll find the various links that contain the information your looking for.

Good Luck!

Thanks for continuous guideline!

Our Nortel IP-Phones model is:NTYS02, Series: 1110. As you told, by loading SIP firmware we can use these IP Phones with any SIP softswitch. right? If so, what is solution to get the interface of IP-Phone to configure it with any SIP server?

Regards,

– Sajid

Nortel IP phones will only work with Nortel based Call Servers, Succession 1000 (CS1K) or Business Communications Manager (BCM), out of the box. With that said, depending on the model of your phone you can load SIP firmware onto an 1120e/1140e phones can get them to connect to any SIP compliant solution.

Good Luck!

Thanks for cmment!

As I mentioned in my previous post that we have just bought new Nortel IP Phones to use with our existing IPPBX. Before we were using diferent IP Phones and those are working properly. Nortel phone recently we bought and when I tried to configure them and connected them to our LAN immidiately they are displaying message “DHCP Parse Error”

So advice me, can I configure the Nortel IP Phones with any 3rd party IP-PBX? and How I get rid of this “DHCP Parse Error”. I read your posts but I couldn’t get them. :( Just please advice me how can I confgure Nortel Ip Phones with any 3rd party system?

I shall be thankful!

Regards,

– SAjid

I believe the article above points out several possible problems that can lead to a “DHCP Parse Error”.

It’s assumed that you’ve configured the phone, switch and DHCP server appropriately.

Good Luck!

We just recently bought Nortel 1110 series IP Phones to connect with our IP PBX system. But when I connected the IP phone to LAN, it was displaying DHCP parse error. Kindly anybody tell me the simple solution to fix this problem.

Thanks in advance!

Sajid

Currently i am having this problem where if connecting to Switch 2950, it can’t work, but to Switch 3560, it can work. Have you face with this problem before?

Thanks !