Connecting Customer Trunk with QinQ

So, straight to the point, below is the diagram:

Sw-PE-1 and Sw-PE-2 is the Service Provider edge Switches. Sw-CE-1 and Sw-CE2 is the customer switches that have dot1q trunk connection . R1, R2, R5 and R6 is the customer routers.

R1 and R2 are in the VLAN 100 segment and have IP Network 100.100.1.0/24. R5 and R6 are in the VLAN 34 segment and have IP Network 10.10.10.0/24. The trunk between Sw-CE-1 and Sw-CE-2 just allowed VLAN 34 and 100 to traverse over it. Sw-PE-1 connected to Sw-CE-1 as a dot1q-tunnel, same like the connection from Sw-PE-2 to Sw-CE-2. Sw-PE-1 connected to Sw-PE-2 via Etherchannel.

The scenario is to make (R1 and R2) and (R5 and R6) are in the same broadcast domain. Beside that, the CDP and VTP information will pass the trunk between Sw-CE-1 and Sw-CE-2.

Below is the relevant configuration and verifying process to fulfil the scenario above (Just show the Layer 3 connection between R1 and R2 and Layer 2 Connection between Sw-CE-1 and Sw-CE-2):

Sw-PE-1:

Sw-PE-1#sh run int f0/15
interface FastEthernet0/15
description To-Sw-1
switchport access vlan 12
switchport mode dot1q-tunnel
l2protocol-tunnel cdp
l2protocol-tunnel vtp
no cdp enable
end

Sw-PE-1#sh int f0/15 switchport
Name: Fa0/15
Switchport: Enabled
Administrative Mode: tunnel
Operational Mode: tunnel
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: native
Negotiation of Trunking: Off
Access Mode VLAN: 12 (VLAN0012)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none

Sw-PE-1#show l2protocol-tunnel interface f0/15 summ
COS for Encapsulated Packets: 5
Port Protocol Shutdown Drop Status
Threshold Threshold
(cdp/stp/vtp) (cdp/stp/vtp)
(pagp/lacp/udld) (pagp/lacp/udld)
——- ———– —————- —————- ———-
Fa0/15 cdp — vtp —-/—-/—- —-/—-/—- up
—- —- —- —-/—-/—- —-/—-/—-

Sw-PE-2:

Sw-PE-2#sh run int f0/16
interface FastEthernet0/16
switchport access vlan 12
switchport mode dot1q-tunnel
l2protocol-tunnel cdp
l2protocol-tunnel vtp
no cdp enable
end

Sw-PE-2#sh int f0/16 switchport
Name: Fa0/16
Switchport: Enabled
Administrative Mode: tunnel
Operational Mode: tunnel
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: native
Negotiation of Trunking: Off
Access Mode VLAN: 12 (VLAN0012)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none

Sw-PE-2#sh l2protocol-tunnel summary
COS for Encapsulated Packets: 5
Drop Threshold for Encapsulated Packets: 0
Port Protocol Shutdown Drop Status
Threshold Threshold
(cdp/stp/vtp) (cdp/stp/vtp)
(pagp/lacp/udld) (pagp/lacp/udld)
——- ———– —————- —————- ———-
Fa0/16 cdp — vtp —-/—-/—- —-/—-/—- up
—- —- —- —-/—-/—- —-/—-/—-

Sw-CE-1:

Sw-CE-1#sh run int f0/18
interface FastEthernet0/18
description To-Sw-3
switchport trunk encapsulation dot1
switchport trunk allowed vlan 34,10
switchport mode trunk
end
Sw-CE-1#sh run int f0/1
interface FastEthernet0/1
switchport access vlan 100
switchport mode access
end
Sw-CE-1#sh run int f0/5
interface FastEthernet0/5
switchport access vlan 34
switchport mode access
end
Sw-CE-1#

Sw-CE-1#sh int trunk
Port Mode Encapsulation Status Native vlan
Fa0/18 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa0/18 34,100
Port Vlans allowed and active in management domain
Fa0/18 34,100
Port Vlans in spanning tree forwarding state and not pruned
Fa0/18 34,100
Sw-CE-1#

Verify that CDP information can pass the trunk link

Sw-CE-1#sh cdp nei
Capability Codes: R – Router, T – Trans Bridge, B – Source Route Bridge
S – Switch, H – Host, I – IGMP, r – Repeater, P – Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
Sw-CE-2 Fas 0/18 161 S I WS-C3560G Gig 0/19
R1 Fas 0/1 133 R S I 3825 Gig 0/0
R5 Fas 0/5 128 R S I 2811 Fas 0/0
Sw-CE-1#

Sw-CE-2:

Sw-CE-2#sh run int g0/19
interface GigabitEthernet0/19
description To-Sw-4
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 34,100
switchport mode trunk
end
Sw-CE-2#sh run int g0/6
interface GigabitEthernet0/6
switchport access vlan 34
switchport mode access
end
Sw-CE-2#sh run int g0/2
interface GigabitEthernet0/2
switchport access vlan 100
switchport mode access
end

Sw-CE-2#sh int trunk
Port Mode Encapsulation Status Native vlan
Gi0/19 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi0/19 34,100
Port Vlans allowed and active in management domain
Gi0/19 34,100
Port Vlans in spanning tree forwarding state and not pruned
Gi0/19 34,100

Verify that CDP information can pass the trunk link

Sw-CE-2#sh cdp nei
Capability Codes: R – Router, T – Trans Bridge, B – Source Route Bridge
S – Switch, H – Host, I – IGMP, r – Repeater, P – Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
Sw-CE-1 Gig 0/19 130 S I WS-C3560- Fas 0/18
BB2 Gig 0/24 140 R S I 2821 Gig 0/0
R2 Gig 0/2 171 R S I 3825 Gig 0/1
R6 Gig 0/6 158 R S I 2811 Fas 0/1
Sw-CE-2#

Verify that VTP (VLAN Trunking Protocol can pass the trunk link between Sw-CE-1 and Sw-CE-2 (In this scenario, Sw-CE-1 is VTP Server and Sw-CE-2 is the VTP client. The VTP domain is CISCO):

Sw-CE-1#sh vtp status
VTP Version : 2
Configuration Revision : 4
Maximum VLANs supported locally : 1005
Number of existing VLANs : 7
VTP Operating Mode : Server
VTP Domain Name : CISCO
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0×13 0xA1 0xBA 0x0E 0xC2 0x2A 0xC9 0xCE
Configuration last modified by 10.10.34.1 at 3-1-93 01:16:52
Local updater ID is 10.10.34.1 on interface Vl34 (lowest numbered VLAN interface
found)
Sw-CE-1#sh vlan | i 100
100 100-VLAN active Fa0/1
100 enet 100100 1500 – – – – – 0 0

Sw-CE-2#sh vtp status
VTP Version : 2
Configuration Revision : 4
Maximum VLANs supported locally : 1005
Number of existing VLANs : 7
VTP Operating Mode : Client
VTP Domain Name : CISCO
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0×13 0xA1 0xBA 0x0E 0xC2 0x2A 0xC9 0xCE
Configuration last modified by 10.10.34.1 at 3-1-93 01:16:52
Sw-CE-2#sh vlan | i 100
100 100-VLAN active Gi0/2
100 enet 100100 1500 – – – – – 0 0
Sw-CE-2#

R1:

R1#sh run int g0/0
interface GigabitEthernet0/0
description To-Sw-1
ip address 100.100.1.1 255.255.255.0
duplex auto
speed auto
media-type rj45
negotiation auto
end

R2:

R2#sh run int g0/1
interface GigabitEthernet0/1
ip address 100.100.1.2 255.255.255.0
duplex auto
speed auto
media-type rj45
negotiation auto
end

So, let we verify the Layer 3 connection between R1 and R2

R1#ping 100.100.1.2
Sending 5, 100-byte ICMP Echos to 100.100.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

R2#ping 100.100.1.1
Sending 5, 100-byte ICMP Echos to 100.100.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

Verify that R1 G0/0 and R2 G0/1 are in the same broadcast domain

R1#ping 255.255.255.255 repeat 1
Sending 1, 100-byte ICMP Echos to 255.255.255.255, timeout is 2 seconds:
Reply to request 0 from 100.100.1.2, 1 ms

R1#sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 100.100.1.1 – 001b.d57e.7190 ARPA GigabitEthernet0/0
Internet 100.100.1.2 138 001b.d57e.7311 ARPA GigabitEthernet0/0

R2#ping 255.255.255.255 rep 1
Sending 1, 100-byte ICMP Echos to 255.255.255.255, timeout is 2 seconds:
Reply to request 0 from 100.100.1.1, 1 ms
R2#sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 100.100.1.1 139 001b.d57e.7190 ARPA GigabitEthernet0/1
Internet 100.100.1.2 – 001b.d57e.7311 ARPA GigabitEthernet0/1