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Troubleshooting
There are no troubleshooting steps for this task.
Configuring the Inter−VLAN Router
This subtask provides the partial configuration required for any Cisco IOS Software−based router that
supports 802.1Q trunking over a Fast Ethernet port. If you would like to review the concepts involved in
configuring inter−VLAN routing, refer to Routing Between VLANs Overview. General information on
VLANs and Trunking can be found on the VLANs (Virtual LANs) & VTP (VLAN Trunking Protocol)
Technical Support page.
This partial configuration establishes an 802.1Q trunk between the Catalyst 2924 XL and the inter−VLAN
router:
!
ip dhcp smart−relay
!
interface FastEthernet0/0
description Native VLAN Trunk to Cat2924XL
ip address 10.21.7.72 255.255.255.0
ip helper−address 10.21.15.10
ip dhcp relay information trusted speed auto
!
interface FastEthernet0/0.1
description VLAN2 Trunk to Cat2924XL
encapsulation dot1Q 2
ip address 10.21.8.72 255.255.255.0
ip helper−address 10.21.15.10
ip dhcp relay information trusted
!
!
interface FastEthernet0/0.8
description VLAN9 Trunk to Cat2924XL
encapsulation dot1Q 9
ip address 10.21.15.72 255.255.255.0
ip helper−address 10.21.15.10
ip dhcp relay information trusted
!
Verifying
Issue the show vlan 1 command to verify that the native (VLAN1) inter−VLAN router port is configured
correctly. In this sample output, you can see that traffic is passing in both directions over this trunk:
Router# show vlan 1
Virtual LAN ID: 1 (IEEE 802.1Q Encapsulation)
vLAN Trunk Interface: FastEthernet0/0
This is configured as native Vlan for the following interface(s):
FastEthernet0/0
Protocols Configured: Address: Received: Transmitted:
IP 10.21.7.72 6315069 5625671
Issue the show vlan 2 command to verify that the VLAN2 inter−VLAN router port is configured correctly. In
this sample output, you can see that traffic is passing in both directions over this trunk: