2800 with NDM-36-ESW Vlan problem

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Apr 6th, 2007
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I am setting up the above for Avaya phones. The sites with separate router/switch combos work fine.

The FA port settings are as follows:


interface FastEthernet1/2

description * Data/Voice Vlan's *

switchport access vlan 20

switchport voice vlan 852

mls qos trust dscp

spanning-tree portfast

We have 2 Vlan interfaces set up - 1 for voice and one for data. (20 is data and 852 is voice.

If I plug a laptop in, I get an IP address from the off-site DHCP server.

If I plug the phone in, it get the Vlan number (852) from the scope option properly.

If I change the port to

switchmode access vlan 852

and plug the laptop in, I get a voice IP address.

If I plug the phone in, it gets it's voive IP address and loads it's config. But I can't get a data IP for the PC.

I do a show vlan-sw and see that all of the ports are assigned to Vlan 20 but none are co-assigned to Vlan 852.

The 3550's, 3750's, etc. at other sites have both Vlan's assigned to each port.

What am I missing?



But on this setup, when I do a sho vlan-sw,

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Overall Rating: 3 (2 ratings)
Brandon Buffin Fri, 04/06/2007 - 13:00
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Try a config such as the following:

interface FastEthernet1/2

description * Data/Voice Vlan's *

switchport trunk encapsulation dot1q

switchport mode trunk

switchport trunk native vlan 20

switchport voice vlan 852

mls qos trust dscp

spanning-tree portfast

Hope this helps. If so, please rate the post.


gregoryt Mon, 04/09/2007 - 05:32
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I loaded this config this morning remotely. I still do not see the interface in the vlan table. It is now in VLAN 1

VLAN Name Status Ports

---- -------------------------------- --------- -------------------------------

1 default active Fa1/2

20 VLAN_20 active Fa1/1, Fa1/3, Fa1/4, Fa1/5, Fa1/6, Fa1/7, Fa1/8, Fa1/9, Fa1/10

Fa1/11, Fa1/12, Fa1/13, Fa1/14, Fa1/15, Fa1/16, Fa1/18, Fa1/19

Fa1/20, Fa1/21, Fa1/22, Fa1/23, Fa1/24, Fa1/25, Fa1/26, Fa1/27

Fa1/28, Fa1/29, Fa1/30, Fa1/31, Fa1/32, Fa1/33, Fa1/34, Fa1/35

852 VLAN_852 active Fa1/0

Doing a show int fa 1/2 trunk gives me this:

Port Mode Encapsulation Status Native vlan

Fa1/2 on 802.1q not-trunking 20

Port Vlans allowed on trunk

Fa1/2 none

Port Vlans allowed and active in management domain

Fa1/2 none

Port Vlans in spanning tree forwarding state and not pruned

Fa1/2 none

The site is an hour or so away. I am heading over ther now to see if the phone works in spite of not seeing the voice vlan on the interface.

Any ideas on why this is?



gregoryt Mon, 04/09/2007 - 17:23
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All is working .. Thanks. Still not sure why it shows in Vlan 1 though.

Hieu Cao Fri, 04/06/2007 - 13:11
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When you use the command "switchportmode access vlan 852", you basically assign that port to have access to vlan 852 ONLY - that's why you get the voice's ip address when you plugged your laptop in this port.

You should use this config:

switchport mode access

switchport access vlan 20

switchport voice vlan 852




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