16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series
Configuration Tasks
50
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
3 packets output, 1074 bytes, 0 underruns(0/0/0)
0 output errors, 0 collisions, 5 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Router#
Configuring a Description for an Interface
You can add a description about an interface to help you remember its function. The description appears
in the output of the following commands: show configuration, show running-config, and show
interfaces.
To add a description for an interface, use the description command in interface configuration mode:
Configuring an Ethernet Interface as a Layer 2 Trunk
To configure an Ethernet interface as a Layer 2 trunk, use the following commands beginning in global
configuration mode:
Note
Ports do not support Dynamic Trunk Protocol (DTP). Ensure that the neighboring switch is set to a mode
that will not send DTP.
Command
Purpose
Step 1
Router(config-if)#
description
string
Adds a description for an interface.
Command
Purpose
Step 1
Router(config)#
interface
{
ethernet
|
fastethernet
}
slot
/
port
Selects the interface to configure.
Step 2
Router(config-if)#
shutdown
(Optional) Shuts down the interface to prevent traffic flow
until configuration is complete.
Note
Encapsulation is always dot1q.
Step 3
Router(config-if)#
switch port mode
trunk
Configures the interface as a Layer 2 trunk.
Step 4
Router(config-if)#
switch port
trunk
native
vlan
vlan-num
For 802.1Q trunks, specifies the native VLAN.
Step 5
Router(config-if)#
switch port trunk allowed vlan
{
add
|
except
|
none
|
remove
}
vlan1
[
,
vlan
[
,
vlan
[
,
...
]]
(Optional) Configures the list of VLANs allowed on the
trunk. All VLANs are allowed by default. You cannot
remove any of the default VLANs from a trunk.
Step 6
Router(config-if)#
no shutdown
Activates the interface. (Required only if you shut down
the interface.)
Step 7
Router(config-if)#
end
Exits configuration mode.