Configuration :
@SW1
interface Ethernet0/0
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Ethernet0/1
switchport access vlan 100
switchport mode dot1q-tunnel
l2protocol-tunnel point-to-point lacp
!
interface Ethernet0/2
switchport access vlan 200
switchport mode dot1q-tunnel
l2protocol-tunnel point-to-point lacp
@SW2
interface Ethernet0/0
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Ethernet0/1
switchport access vlan 100
switchport mode dot1q-tunnel
l2protocol-tunnel point-to-point lacp
!
interface Ethernet0/2
switchport access vlan 200
switchport mode dot1q-tunnel
l2protocol-tunnel point-to-point lacp
!
Note:
the reason you need to separate the metro tag is that : to prevent the case where the packet leaves SW3 is routed it self is reset at SW2 and foreword over both interface to SW4, and this is case L2 loop.
@SW3
interface Ethernet0/1
channel-group 1 mode active
!
interface Ethernet0/2
channel-group 1 mode active
@SW4
interface Ethernet0/1
channel-group 1 mode active
!
interface Ethernet0/2
channel-group 1 mode active
verification
@SW4 and 3
SW4#sh etherchannel summary
Flags: D - down P - bundled in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
U - in use N - not in use, no aggregation
f - failed to allocate aggregator
M - not in use, minimum links not met
m - not in use, port not aggregated due to minimum links not met
u - unsuitable for bundling
w - waiting to be aggregated
d - default port
A - formed by Auto LAG
Number of channel-groups in use: 1
Number of aggregators: 1
Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
1 Po1(SU) LACP Et0/1(s) Et0/2(P)
Note:
for some reason the native vlans for CE and PE is match, the traffic from CE will be lake in ISP without metro tag, there for the traffic will be drop and maybe case L2 loop, to prevent that you should use "vlan dot1q tag native" on Global mode for all ISP devices.
for more information about dot.1Q Tunneling and Native VLANs problem go to this link :
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/12-2_55_se/configuration/guide/3750xscg/swtunnel.html
thank you.
Ameer Alsafi
09/05/16
