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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 5 Configuring Ethernet VLAN Trunks
Example VLAN Trunk Configurations
Figure 5-1
ISL Trunk Over Fast EtherChannel Link
To configure the switches to form a two-port EtherChannel bundle and then configure the EtherChannel
bundle as an ISL trunk link, perform these steps:
Step 1
Confirm the channeling and trunking status of the switches by entering the
show port channel
and
show
trunk
commands.
Switch_A> (enable)
show port channel
No ports channelling
Switch_A> (enable)
show trunk
No ports trunking.
Switch_A> (enable)
Switch_B> (enable)
show port channel
No ports channelling
Switch_B> (enable)
show trunk
No ports trunking.
Switch_B> (enable)
Step 2
Configure the ports on Switch A to negotiate an EtherChannel bundle with the neighboring switch by
entering the
set port channel
command. This example assumes that the neighboring ports on Switch B
are in EtherChannel
auto
mode. The system logging messages provide information about the formation
of the EtherChannel bundle.
Switch_A> (enable)
set port channel 1/1-2 desirable
Port(s) 1/1-2 channel mode set to desirable.
Switch_A> (enable) %PAGP-5-PORTFROMSTP:Port 1/1 left bridge port 1/1
%PAGP-5-PORTFROMSTP:Port 1/2 left bridge port 1/2
%PAGP-5-PORTFROMSTP:Port 1/2 left bridge port 1/2
%PAGP-5-PORTTOSTP:Port 1/1 joined bridge port 1/1-2
%PAGP-5-PORTTOSTP:Port 1/2 joined bridge port 1/1-2
Switch_B> (enable) %PAGP-5-PORTFROMSTP:Port 3/1 left bridge port 3/1
%PAGP-5-PORTFROMSTP:Port 3/2 left bridge port 3/2
%PAGP-5-PORTFROMSTP:Port 3/2 left bridge port 3/2
%PAGP-5-PORTTOSTP:Port 3/1 joined bridge port 3/1-2
%PAGP-5-PORTTOSTP:Port 3/2 joined bridge port 3/1-2
Step 3
After the EtherChannel bundle is negotiated, verify the configuration by entering the
show port channel
command.
Switch_A> (enable)
show port channel
Port Status Channel Channel Neighbor Neighbor
mode status device port
----- ---------- --------- ----------- ------------------------- ----------
1/1 connected desirable channel WS-C5000 009979082(Sw 3/1
1/2 connected desirable channel WS-C5000 009979082(Sw 3/2
----- ---------- --------- ----------- ------------------------- ----------
Switch_A> (enable)
Switch_B> (enable)
show port channel
Port Status Channel Channel Neighbor Neighbor
Switch A
Switch B
1/1
1/2
3/1
3/2
Fast EtherChannel
ISL trunk link
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