Specifications

Engineering Guidelines
306
Interface fa0/5 is the VLAN trunk connection between Switch 1 and Switch 2. For Ethernet
priority information to be sent between the switches the VLAN trunk must be configured.
Ethernet Switch 2 configuration
There are two connections shown on the example topology for Ethernet Switch 2.
1. Fa0/2 to IP Phone extension 2002
2. Fa0/24 to Ethernet Switch 1
In this example VLANs are being assigned to the IP phones using CDP. Configurations for each
port follow (assumes no VTP):
These steps are to set up QoS on the Catalyst 3550 and create the Voice VLAN.
Switch1(config-if)# switchport mode trunk [sends VLAN information across the link]
Switch1(config-if)# priority-queue out [makes queue 4 a strict priority queue]
Switch1(config-if)# exit
Switch1(config)# interface fa0/24 [connection to Router 1 fa0/0]
Switch1(config-if)# description "Connection to Router 1
fa0/1 - Voice"
Switch1(config-if)# switchport trunk encapsulation dot1q [Forces 802.1Q frame]
Switch1(config-if)# switchport mode trunk [sends VLAN information across the link]
Switch1(config-if)# priority-queue out [makes queue 4 a strict priority queue]
Switch1(config-if)# exit
Interface fa0/24 is connected to the router.
Switch2# configure terminal
Switch2(config)# mls qos [sets up QOS on the switch globally]
Switch2(config)# vlan 100 [create the voice VLAN]
Switch2(config-vlan)# name VoiceVLAN [Give it a name]
Switch2(config-vlan)# exit
Switch2(config)# interface fa0/2 [the connection to the ext. 2002]
Switch2(config-if)# description "Connection to
Ext.2002"
Switch2(config-if)# switchport mode access [port defaults to standard Ethernet frame]
Switch2(config-if)# switchport voice vlan 100 [allows the IP set to learn the VLAN via CDP]
Switch2(config-if)# mls qos trust dscp pass-through
cos
[required to allow DSCP & 802.1p through]
Switch2(config-if)# priority-queue out
Switch2(config-if)# spanning-tree portfast [bypasses the spanning the startup procedure]
Switch2(config-if)# spanning-tree bpdufilter enable [stops spanning tree messages from being sent]