Dual Vlan on switch port ?

[renzil]

Hi,

Need to configure dual vlan on a switchport. which is the right way to configure the same

interface FastEthernet0/1

switchport trunk encapsulation dot1q

switchport trunk native vlan 10

switchport mode trunk

switchport voice vlan 100

no ip address

srr-queue bandwidth share 10 10 60 20

srr-queue bandwidth shape 10 0 0 0

mls qos trust device cisco-phone

mls qos trust cos

no mdix auto

auto qos voip cisco-phone

spanning-tree portfast

or

interface FastEthernet0/1

switchport access vlan 10

switchport voice vlan 100

no ip address

srr-queue bandwidth share 10 10 60 20

srr-queue bandwidth shape 10 0 0 0

mls qos trust device cisco-phone

mls qos trust cos

no mdix auto

auto qos voip cisco-phone

spanning-tree portfast

Rgds

Renzil

[tony.hanson]

The first one is correct to have voice and data on the same port, I do see that you are also running auto qos. So use this one:

interface FastEthernet0/1

switchport trunk encapsulation dot1q

switchport trunk native vlan 10

switchport mode trunk

switchport voice vlan 100

no ip address

srr-queue bandwidth share 10 10 60 20

srr-queue bandwidth shape 10 0 0 0

mls qos trust device cisco-phone

mls qos trust cos

no mdix auto

auto qos voip cisco-phone

spanning-tree portfast

[dpmichaud]

Actually the second is better, if you trunk, all your vlan information is transfered to your phones as well, the 2nd option will not do this. This is info from Cisco tac, not to sure about the qos.

[allan.thomas]

This is not necessarily the case, you can prune or restric vlans by configuring switchport trunk allowed vlan 10,100 on the fastethernet interface.

However, pruning or restricting vlans should be applied on the uplink from the destribution layer. Although there are instances where multiple vlans are required to the access-layer, I would be inclined to prune or allow only the voice, and data vlan on the IP Phone trunk port.

One other consideration, specifically concerning QOS or Auto-qos, and that is auto-qos configuration may not specifically suit your traffic profile, and may require adjusting.

[renzil]

Thanks guys for ur reviews,

So then shud I go with the first option without auto-qos and enable vlan pruning only for my data and voice vlan on the ip phone trunk ports ?

Rgds

Renzil

[allan.thomas]

Personally, and in my experience yes.

[qvist-a]

Hi,

This is interesting because I wonder the same thing.

Why set the port in trunk if you just want separat vlan for phone and pc.

Anders

Sweden

[allan.thomas]

Since dot1q does not tag the native VLAN, you need to use the switch-wide CoS configuration to tag such packets.

These tags are retained through the switch and used in output scheduling. If the outgoing port is a trunk as in this case, then the original CoS value or the new value (for packets that arrive untagged on native VLAN) is tagged in the packet.