Mapping 802.1Q Vlans To Isl Vlans - Cisco 7609 Configuration Manual

Chapter 9 Configuring VLANs
This example shows how to configure descending as the internal VLAN allocation policy:
Router# configure terminal
Router(config)# vlan internal allocation policy descending

Mapping 802.1Q VLANs to ISL VLANs

The valid range of user-configurable ISL VLANs is 1 through 1001 and 1006 through 4094. The valid
range of VLANs specified in the IEEE 802.1Q standard is 1 to 4094. You can map 802.1Q VLAN
numbers to ISL VLAN numbers.
802.1Q VLANs in the range 1 through 1001 and 1006 through 4094 are automatically mapped to the
corresponding ISL VLAN. 802.1Q VLAN numbers corresponding to reserved VLAN numbers must be
mapped to an ISL VLAN in order to be recognized and forwarded by Cisco network devices.
These restrictions apply when mapping 802.1Q VLANs to ISL VLANs:
•
•
•
•
•
To map an 802.1Q VLAN to an ISL VLAN, perform this task:
Command
Step 1
Router(config)# vlan mapping dot1q dot1q_vlan isl
isl_vlan
Router(config)# no vlan mapping dot1q {all |
dot1q_vlan}
Step 2
Router(config)# end
Step 3
Router# show vlan
This example shows how to map 802.1Q VLAN 1003 to ISL VLAN 200:
Router# configure terminal
Router(config)# vlan mapping dot1q 1003 isl 200
Router(config)# end
Router#
This example shows how to verify the configuration:
Router# show vlan
<...output truncated...>
802.1Q Trunk Remapped VLANs:
802.1Q VLAN
-----------
1003
78-14064-04
You can configure up to eight 802.1Q-to-ISL VLAN mappings on the Cisco 7600 series router.
You can only map 802.1Q VLANs to Ethernet-type ISL VLANs.
Do not enter the native VLAN of any 802.1Q trunk in the mapping table.
When you map an 802.1Q VLAN to an ISL VLAN, traffic on the 802.1Q VLAN corresponding to
the mapped ISL VLAN is blocked. For example, if you map 802.1Q VLAN 1007 to ISL VLAN 200,
traffic on 802.1Q VLAN 200 is blocked.
VLAN mappings are local to each Cisco 7600 series router. Make sure you configure the same
VLAN mappings on all appropriate network devices.
ISL VLAN
-----------
200
Purpose
Maps an 802.1Q VLAN to an ISL Ethernet VLAN. The
valid range for dot1q_vlan is 1001 to 4094. The valid
range for isl_vlan is the same.
Deletes the mapping.
Exits configuration mode.
Verifies the VLAN mapping.
Cisco 7600 Series Router Cisco IOS Software Configuration Guide—12.1E
Configuring VLANs
9-13