Thursday, July 17, 2008

Switching - Dot1q and L2 protocol tunneling

This is a pretty fairly simple lab, but I had never done dot1q tunneling so I wanted to keep it simple.

Network:

[R2 ]---vlan 4---------------[sw1]
[sw1]---asymmetric trunk---[sw2]
[sw2]---dot1q trunk---------[sw3]
[sw3]---asymmetric trunk---[sw4]
[sw4]---vlan 4---------------[R4 ]

Here are the relevant configs with descriptions under the interfaces. Note that the R2 and R4 fastethernet interfaces are on the subnet 192.168.0.0/24.

SW1:
!
interface FastEthernet0/2
description to R2 f0/0
switchport access vlan 4
switchport mode access
!
interface FastEthernet0/12
description to SW2 f0/12
switchport trunk encapsulation dot1q
switchport mode trunk


SW2:
!
interface FastEthernet0/12
description to SW1 f0/12
switchport access vlan 30
switchport mode dot1q-tunnel
!
interface FastEthernet0/23
description to SW3 f0/23
switchport trunk encapsulation dot1q
switchport trunk native vlan 23
switchport mode trunk


SW3:
!
interface FastEthernet0/23
description to SW2 f0/23
switchport trunk encapsulation dot1q
switchport trunk native vlan 23
switchport mode trunk
!
interface FastEthernet0/24
description to SW4 f0/24
switchport access vlan 30
switchport mode dot1q-tunnel


SW4:
!
interface FastEthernet0/4
description to R4 f0/0
switchport access vlan 4
switchport mode access
!
interface FastEthernet0/24
description to SW3 f0/24
switchport trunk encapsulation dot1q
switchport mode trunk


Ping from R2 to R4:

R2#ping 192.168.0.4

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.0.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/38/52 ms
R2#


Now let's say I want SW1 and SW4 to see each other as CDP neighbors. And I also want SW1 to be a VTP server and SW4 to be a VTP client.

SW2:

interface FastEthernet0/12
description to SW1 f0/12
l2protocol-tunnel cdp
l2protocol-tunnel vtp


SW3:

interface FastEthernet0/24
description to SW4 f0/24
l2protocol-tunnel cdp
l2protocol-tunnel vtp


Verify CDP tunneling, SW1 and SW4 are NOT directly connected!

SW4:

SW4#show cdp ne

Device ID Local Intrfce Holdtme Capability Platform Port ID
SW1 Fas 0/24 125 R S I WS-C3560-2 Fas0/12
R4 Fas 0/4 132 R 3640 Fas0/0


Verify VTP tunneling:

SW1:

SW1(config)#vlan 13
SW1(config-vlan)#name test


SW4:

SW4#show vtp status | inc Oper
VTP Operating Mode : Client

SW4#show vlan brief | inc 13
13 test active

Pretty cool, eh? That's it for now...

1 comment:

  1. Thank you for the great web site - a true resource, and one many people clearly enjoy thanks for sharing the info, keep up the good work going....

    ReplyDelete

Note: Only a member of this blog may post a comment.