Dual DHCP operation thru CXi PoE ports (MCD 4.0 sp1)

[Jakt99]

Can someone assist or clarify? I am new to Mitel world and a tad confused with IP settings within 3300 ICP.

What I am attempting to achieve is, to segragate voice and data vlan thru Cxi Port switch and untilise two dhcp servers as follows. If possible be able to attached a data device (printer or PC) direct to Cxi Port as well as piggy backup behind IP handset. No requirement for external L2 switch (Only 9 IP handsets, 9 PC's, 1 Micosoft server and 2 Printer)

Data devices operate on vlan 1 untagged - DHCP from Corp server (192.168.1.0 subnet)

Voice devices operate on vlan 2 (tagged) - DHCP from embedded Cxi (192.168.2.0 subnet)

Routing between the two subnets performed by local cisco router. Gateways are vlan 1 =192.168.1.254, vlan 2 = 192.168.2.254

I can't seem to prevent data devices picking off an IP addresse from the Cxi.

cheers

 

[kwbMitel]

Name your range "ipphone.mitel.com"

use option 125

DHCP will only hand out addresses to IP Phones

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Occam's Razor - All things being equal, the simplest solution is the right one.

 

[Jakt99]

Thanks kwbMitel for response

So to clarify...

I am using option 125 set as follows for call server as 192.168.2.2 and vlan 2 (hopefully copied across ok?):

id:ipphone.mitel.com;sw_tftp=192.168.2.2;call_srv=192.168.2.2;vlan=2;l2p=6;dscp=46;

and next, more importantly

Enter a name, EG your suggested name "ipphone.mitel.com" in the name field in the "DHCP IP range form" of ICP

Will give it a go.....

cheers

 

[danramirez]

Before telling you how I did it, I need to know a couple of things:

1. Will you be using the 3300 as your DHCP server for both scopes, won't you?
2. Have you programmed your CISCO router with the HELPER option? This will tell the other VLAN where to look for a DHCP Server. I don't know how to do it on a CISCO as I work with Allied Telesis products. I am pretty sure you can find that on the Techs Handbook at the end of the book (Appendixes).
3. Where are you connecting the CISCO to the 3300 CXi, port 17?.

There's only one thing I don't like from this configuration, but it doesn't cause any harm to the network. You will get 2 gateways from the DHCP. If you do a ipconfig on your PC you will see two gateways.

Regards,

Daniel

 

[Jakt99]

Hi Danramirez

Thanks for info and suggestion.

The scenario I pose is a client requirement to segragate the two domains. Basically the router provides connectivity between subnets for management only.

I have perused a couple of Mitel documents that illustrate my scenario in basic diagram concepts, but doesn't demonstrate how to implement in the real world. So in theory can be implemented.

I have tried playing about with the vlan tag settings of the embedded PoE switch without sucesss. IE same result, any device attached picks up an ip address from the mitel dhcp server.

Correct, the router will be on port 17 and vlan trunking implemented accordingly:

- vlan 2, voice tagged
- vlan 1, data untagged (native)

I believe I wont need a IP helper command in the router, by default all attached devices will operate initially in vlan 1 (IP Phones subsequently switch to vlan 2).

A Mitel phone dhcp b'cast request will only be recognised and picked by the 3300 dhcp server, the subsequent reply allow it to tag itself with vlan 2. Mitel IP phones will ignore any offers sent from the MS dhcp server because relevant voice options wont be sent.

By configuring the 3300 DHCP range parameters suggested by kwbmitel, hopefully all NON MITEL device DHCP b'cast requests will be ignored by the 3300 DHCP server and pick up only by the miscrosoft server DHCP.

That's the idea anyway......

cheers

 

[tlpeter]

The phones will try vlan 1 first
You need to tell the phones to look in vlan 2




ACS - Implement IP Office
ACA - Implement IP Telephony -- ACA - Design IP Telephony
ACA - Voice Services Management
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Women and cats can do as they please and men and dogs should relax and get used to the idea!

 

[danramirez]

I am almost sure you will be needing the HELPER... I will copy/paste from the Techs Hand Book... Give me a couple of minutes.

Make note of my email just in case, daniel@wtelecom.com
and skype nickname: daniloanderson

Regards,

Daniel

 

[danramirez]

Go to page 316 on the Techs. Handbook MCD 4.0, also have a look at pages 321 and 322.

Is that the scenario you have?

Also on page 321 you will find:

"Note: You can configure the CXi/MXe/AX internal DHCP server to provide DHCP services to both VLAN 1 and the Voice VLAN. In this case, an external DHCP server would not be required, but the external router in the corporate
network would need to be configured to support routing from VLAN 1 to the Voice VLAN and DHCP forwarding would have to be enabled on the router."

So... if you want your 3300 to be DHCP for both subnets, both Vlans, you will need your external router with DHCP forwarding enabled (HELPER). I'm not sure CISCO calls it HELPER but HP-Procurve does... Allied router calls it DHCP RELAY.

What I've done in the past is:

1. Create two Vlans, VID 2 voice vlan and VID 1 (Default) data vlan.
2. These Vlans must exist on every L2/L3 device in your network, ie. your 3300, your CICO router, etc.
3. Tagg port 17 to voice vlan and leave it untagged to data vlan.
4. Connect your router on port 17 of your 3300. The port on your router must be tagged to voice vlan and untagged to the data vlan. I don't know how cisco calls the tagged and untagged ports... I've heard they call it trunks or voice vlans, etc... Find that out youself.
5. Give an IP to every interface on your Cisco, ie. 192.168.1.1/24 and 192.168.2.1/24.
6. Give an IP to your 3300, ie 192.168.2.10
7. Program TWO scopes on your 3300 DHCP, one for 192.168.1.0 and the second on for 192.168.2.0.
8. Make your router to forward DHCP broadcasts to 192.168.2.10.
9. For your option 3 (Gateway) type in the two interfaces of your router separated by a coma. 192.168.1.1 , 192.168.2.1
10. Program your option 125 and include VID 2 for your Voice Vlan.

If you are going to phisically have two DHCPs on your network, don't need the DHCP forward... But don't do it this way, it is not professional to have two DHCPs (Hardwares) in a network. People that do it this way don't know how to program the HELPER option!!

Let me know if this heps.

Regards,

Daniel Ramirez

 

[danramirez]

Almost forget... ALL PORTS ON THE CXi must be tagged to the voice vlan and untagged to the data vlan.

Reagrds,

Daniel Ramirez

 

[Jakt99]

Thanks gents for all your suggestions and help.

I have plenty to work with now. Am off this morning to site to set up. I'll get back with final configs

Have great holidays and new year if I don't respond sooner

cheers

 

[danramirez]

...Keep in mind during set up, that when you Tagg all ports (3300) to the voice vlan, you will not be able to connect to the 3300 unless you connect through a switch that has the uplink port tagged to the voice vlan. Always connect your laptop to an untagged port on the switch (Untagged to voice vlan).

I've heard that there is a command to clear all programing on the L2 switch (3300), good to have it just in case. I will look for it and post it to you.

Will you have Internet access when on site? ...hope so!!

Regards, good luck and wish you great holidays as well,

Daniel Ramirez

 

[Jakt99]

Danramirez

I wasn't able to get on-site to implement changes (Xmas delays)....

Anyway I have drawn up a generic visio diagram and emailed to you for your perusual

cheers