VLAN trunking between Cisco and Nortel

[nicholasbgr]

Hello everyone. I've been trying for a couple of days to interconnect a Catalyst 3750G and a Nortel 4550T and I think I finally managed to do it but I'm still struggling to fully comprehend the steps and commands to do it. I've read a couple of threads here and an article about it and came to these findings:

1- First, of course you create the vlans you want to pass over the trunk (currently I have 20 vlans).

vlan create 2 name Porto-Desktop-1 type port
vlan create 3 name Porto-Phone-1 type port

2 - Then you enable trunking in your uplinks

vlan ports 1/49-50 tagging tagAll

3 - Finally you set the uplinks as a members of all vlans you wish to trunk

vlan members 2-3 49-50

And those are the steps I gathered from my readings but even after this configuration I couldn't get the vlans to communicate between the two switches. It only worked when I tried this command:

vlan ports 49-50 pvid 2

Can you guys explain to me why do I need it? In Cisco devices all you need to do is set 'swicthport mode trunk' to the interface and it immediately sets up all vlans to go over the trunk, so I thought vlan ports 1/49-50 tagging tagAll would accomplish this. Its the first time I deal with Nortel devices so any clarification would be appreciated.

[Dominik]

Hi nicholasbgr,

you can find a great blogpost for your task here:

http://blog.michaelfmcnamara.com/2011/01/802-1q-vlan-tagging-on-a-cisco-catalyst-3750-e/

There are 2 major differnces in configuring a MLT on an Avaya switch and configuring a etherchannel on Cisco devices. On Avaya Switches you have to add every VLAN seperatly to a trunk. Enabling VLAN tagging on a link does not add all VLAN like it is in Cisco world. The PVID of a MLT trunk is like the native VLAN config in Cisco speech. You can decide with the PVID to wich VLAN untagged frames are forwarded.

Good Luck

[nicholasbgr]

Thanks for your reply Dominik.
I'm kinda confused with what I've been reading about trunking and Nortel. From my knowledge of Cisco devices I consider a trunk a link that enables VLAN multiplexing but it seems to me that for Nortel this concept is somewhat different. I'm not using any kind of link aggregation on those uplinks, they go over a single link to my distribution switches.
PS: How do I negate this command?
vlan ports 1/2 pvid 6
Just set the pvid to 1?

[Dominik]

sorry than I missunderstand you.

The feature what you mean is called "tagging" in Avaya speech.

When you enable tagging on a interface the port can handle tagged frames where the VLAN tag is added to the headder of the packet. After enabling tagging you can add multiple VLANs to the interface.

I think you have to add the VLANs to your tagged interface

vlan members add <VLAN ID> <Port ID>

Good Luck

[nicholasbgr]

Thanks for the clarification
Could you tell me how and why the following commands might be used?

filter-tagged-frame
filter-untagged-frame
filter-unregistered-frames

The first two are related to vlan ids and whether to accept or not tagged frames. Am I right?
The third one I'm not familiar with... 

[Dominik]

Yes you are right for the first two options:
filter-tagged-frame  >> filter all tagged frames on a link
filter-untagged-frame  >> filters all untagged frames on a link

filter-unregistered-frames
Here is the oficial Avaya discription for thaat feature:
Enables or disables the port to filter received unregistered packets. Enabling this feature on a
port means that any frames with a VID to which the port does not belong to are discarded.

I had some problems with filter-unregistered-frames in the past on uplinks. I only use it on accessports.

Does the tagged uplink port (trunk) from the ERS4500 >> Catalyst 3750G now work ?

[nicholasbgr]

Yes, it's working now. Actually it was working before I started the thread but I needed to clarify and understand the steps I followed to get it done. Thanks a lot for your help

[Dominik]

THX for the feedback, good to hear that everything work.


I usually explain it to Cisco folks in this way,
in cisco land you have all VLANs on trunk and ristrict the VLANs with the allowed vlan command afterwards.
in Avaya land you have no VLANs on your tagged trunk and have to select the VLANs you would like to have on your trunk.

Cheers

[nicholasbgr]

Hi again. Once again I need your help.
At the company I work we use Avaya IP Phones (models 4610sw and 1608) with Cisco PoE switches. The configurations is very basic, we just set the port connecting the phone to "switchport voice vlan xx". How would I do that on a 4550T? My current configuration is the following:

vlan ports 1/1-48 filter-unregistered-frames disable
vlan ports 1/49-50 tagging tagAll filter-unregistered-frames disable
vlan ports 2/1-48 filter-unregistered-frames disable
vlan ports 2/49-50 tagging tagAll filter-unregistered-frames disable
vlan configcontrol flexible
vlan members 1 NONE
vlan members 2-5,7-19 1/49-50,2/49-50
vlan members 6 1/2,1/49-50,2/49-50
vlan ports 1/2 pvid 6
vlan ports 1/49-50,2/49-50 pvid 2
vlan configcontrol flexible
no auto-pvid


Lets say I want to put port 1/2 on voice vlan 7 and continue to receive traffic for data vlan 6. Would the following commands accomplish this?

vlan members 7 1/2

Are there any additional commands needed?

Thanks!

[Michael McNamara]

You can follow the commands laid out in this post; http://blog.michaelfmcnamara.com/2007/10/nortel-ers-5520-pwr-switch/

You need to set each port to UnTagPVIDOnly and then make the PVID the data vlan and assign both VLANs to the port. You also need to configure the IP phone either manually or with either DHCP or ADAC/LLDP-MED.

Good Luck!

[nicholasbgr]

Thanks for your reply Michael.
I've made the following configurations to port 13 to 24 to enable data vlan 2 and voice vlan 3.

vlan ports 1-12 filter-unregistered-frames disable
vlan ports 13-24 tagging unTagPvidOnly filter-unregistered-frames disable
vlan ports 25-48 filter-unregistered-frames disable
vlan ports 49-50 tagging tagAll filter-unregistered-frames disable
vlan configcontrol flexible
vlan members 1 NONE
vlan members 2-3 13-24,49-50
vlan members 4-19,299 49-50
vlan members 20 1-10,49-50
vlan ports 1-10 pvid 20
vlan ports 13-24 pvid 2
vlan configcontrol flexible
no auto-pvid

Unfortunately this doesn't seem to work. The ip phones won't get a lease from the DHCP server and if I set an static IP it gives me a bad router error but the computer connected to the IP Phone switch port is able to obtain an address just fine. What am I missing? Do I need to configure lldp like on your blog post?

[Flintstone]

Hi nicholasbgr,

I did not see your voice Vlan 3 in the configuration provided?

Have you setup your DHCP string correctly to tell your IP phone which voice Vlan to use?  Also, your IP phone would need to be setup correctly to use 'full' dynamic Vlan configuration via DHCP?

We initially setup our IP phone statically to test that the signalling server etc was accessible via the voice Vlan before using dynamic Vlans via DHCP.

CheerZ and good luck

[nicholasbgr]

Hi nicholasbgr,

I did not see your voice Vlan 3 in the configuration provided?

Have you setup your DHCP string correctly to tell your IP phone which voice Vlan to use?  Also, your IP phone would need to be setup correctly to use 'full' dynamic Vlan configuration via DHCP?

We initially setup our IP phone statically to test that the signalling server etc was accessible via the voice Vlan before using dynamic Vlans via DHCP.

CheerZ and good luck

Hi Flinstone : )
It is on the second bolded line.
The configuration I pasted above worked fine after a firmware upgrade, I'm really grateful for all your help

[Michael McNamara]

You also need to configure the IP phone either manually or with either DHCP or ADAC/LLDP-MED.

I'm assuming your reconfigured the IP phone appropriately?

You should check to make sure that the IP phone grabbed a DHCP IP address in the voice VLAN and not the data VLAN.

Good Luck!