I've been trying to figure this one out for a long time. All I want to do is configure basic router on a stick config between my 2924xl switch and 3640 router. The 3640 has only 10Mb ethernet. I have read that this is supported for dot1q trunking some places, and that it is not in other places. Right now, I actually have it working, but using a strange config.
The way it works now is I have an IP assigned to the physical interface, even though thats not what the documentation says to do. The native VLAN is 1 on both sides.
If I do no ip address on the physical interface and configure e0/0.1 with an ip address and encapsulation dot1q 1 native, inter-vlan routing doesn't work.
The way I have it now works but the output of show interface trunk on the router displays nothing, and VTP won't work. My guess is because it doesn't truly see the trunk. It's just driving me crazy any help appreciated.
Router:
interface Ethernet0/0
description LAN
ip address 10.1.0.1 255.255.255.0
ip access-group firewall-lan in
ip nat inside
ip virtual-reassembly
ip route-cache flow
no ip mroute-cache
full-duplex
auto qos voip
service-policy output AutoQoS-Policy-UnTrust
!
interface Ethernet0/0.2
description wireless VLAN
encapsulation dot1Q 2
ip address 10.1.2.1 255.255.255.0
ip access-group firewall-lan in
ip nat inside
ip virtual-reassembly
!
interface Ethernet0/0.3
description Vonage VLAN
encapsulation dot1Q 3
ip address 10.1.3.1 255.255.255.252
ip nat inside
ip virtual-reassembly
router#show vlans
Virtual LAN ID: 1 (IEEE 802.1Q Encapsulation)
vLAN Trunk Interface: Ethernet0/0
This is configured as native Vlan for the following interface(s) :
Ethernet0/0
Protocols Configured: Address: Received: Transmitted:
IP 10.1.0.1 0 2117
Other 0 640
0 packets, 0 bytes input
2757 packets, 252582 bytes output
Virtual LAN ID: 2 (IEEE 802.1Q Encapsulation)
vLAN Trunk Interface: Ethernet0/0.2
Protocols Configured: Address: Received: Transmitted:
IP 10.1.2.1 12507 11668
Other 0 12
12507 packets, 2132903 bytes input
11680 packets, 9957139 bytes output
Virtual LAN ID: 3 (IEEE 802.1Q Encapsulation)
vLAN Trunk Interface: Ethernet0/0.3
Protocols Configured: Address: Received: Transmitted:
IP 10.1.3.1 467 844
Other 0 88
467 packets, 240776 bytes input
932 packets, 192375 bytes output
Switch:
sh run int fa0/1
Building configuration...
Current configuration:
!
interface FastEthernet0/1
duplex full
speed 10
switchport trunk encapsulation dot1q
switchport mode trunk
end
Switch#sh int fa0/1 switchport
Name: Fa0/1
Switchport: Enabled
Administrative mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: Disabled
Access Mode VLAN: 0 ((Inactive))
Trunking Native Mode VLAN: 1 (default)
Trunking VLANs Enabled: ALL
Trunking VLANs Active: 1-3,69
Pruning VLANs Enabled: 2-1001
Priority for untagged frames: 0
Override vlan tag priority: FALSE
Voice VLAN: none
Appliance trust: none
Self Loopback: No
