From: ccieben@cox.net
Date: Mon Mar 13 2006 - 23:25:08 GMT-3
Hello,
I have the following attached to a 3550:
Port 0/1 - trunked back to a Router A. I am allowing Vlan 10 & 20 & stating that 20 is native.
Port 0/5 - a Vlan 20 access port attached to Router B.
Router A & Router B are both on the same subnet.
With the 3550 in its normal state - Router A & Router B cannot ping each other. Once I add the command:
3550(config)#vlan dot1q tag native
Router A & Router B are able to ping each other... I thought that command would only be useful in an SP environment where 1Q/L2 tunneling was being performed.
I thought these untagged packets were automatically part of vlan 20? What is the logic of why these devices can't "speak".... can someone help me understand the logic?
TIA - Ben
***Router A
interface Ethernet0/0.20
encapsulation dot1Q 20 native
ip address 172.16.17.1 255.255.255.0
end
***Router B
interface FastEthernet0/0
ip address 172.16.17.6 255.255.255.0
end
***3550
interface FastEthernet0/1
description to ROUTER-A
switchport trunk encapsulation dot1q
switchport trunk native vlan 20
switchport trunk allowed vlan 10,20
switchport mode trunk
end
interface FastEthernet0/5
description to ROUTER-B
switchport access vlan 20
switchport mode access
end
3550#show int trun
Port Mode Encapsulation Status Native vlan
Fa0/1 on 802.1q trunking 20
<snip>
This archive was generated by hypermail 2.1.4 : Sat Apr 01 2006 - 10:07:38 GMT-3