Very similar to a single xconnect, having a secondary backup pseudowire allows for failover. Normally this would be configured with a dedicated pseudowire that leverages MPLS Traffic Engineering. The backup PW will be inactive and in standby mode. This is because the MAC addresses that the CE exchange is exchanged in the data plane, if the secondary PW was operational, there would be a MAC recursion issue. Meaning the PE routers wouldn’t know which PW to send out the traffic over. There is no STP running, so to prevent a L2 loop, a PW is de-activated and placed into standby mode.
CSR1
interface GigabitEthernet5
xconnect 192.0.2.5 1 encapsulation mpls
backup peer 192.0.2.5 2 priority 2
CSR5
interface GigabitEthernet3
xconnect 192.0.2.1 1 encapsulation mpls
backup peer 192.0.2.1 2 priority 2
CSR1#show xconnect peer 192.0.2.5 all detail
Legend: XC ST=Xconnect State S1=Segment1 State S2=Segment2 State
UP=Up DN=Down AD=Admin Down IA=Inactive
SB=Standby HS=Hot Standby RV=Recovering NH=No Hardware
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP pri ac Gi5:11(Ethernet) UP mpls 192.0.2.5:1 UP
Interworking: none Local VC label 69
Remote VC label 48
IA sec ac Gi5:11(Ethernet) UP mpls 192.0.2.5:2 SB
Interworking: none Local VC label 71
Remote VC label 49
CSR5#show xconnect peer 192.0.2.1 all detail
Legend: XC ST=Xconnect State S1=Segment1 State S2=Segment2 State
UP=Up DN=Down AD=Admin Down IA=Inactive
SB=Standby HS=Hot Standby RV=Recovering NH=No Hardware
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP pri ac Gi3:9(Ethernet) UP mpls 192.0.2.1:1 UP
Interworking: none Local VC label 48
Remote VC label 69
IA sec ac Gi3:9(Ethernet) UP mpls 192.0.2.1:2 SB
Interworking: none Local VC label 49
Remote VC label 71
CSR5#show l2vpn atom vc
Service
Interface Peer ID VC ID Type Name Status
--------- --------------- ---------- ------ ------------------------ ----------
pw100001 192.0.2.1 1 p2p Gi3-9 UP
pw100003 192.0.2.1 2 p2p Gi3-9 STANDBY
CSR5#show l2vpn atom vc detail
pseudowire100001 is up, VC status is up PW type: Ethernet
Create time: 00:11:13, last status change time: 00:11:13
Last label FSM state change time: 00:11:12
Destination address: 192.0.2.1 VC ID: 1
Output interface: Gi1, imposed label stack {16 69}
Preferred path: not configured
Default path: active
Next hop: 10.3.5.3
Member of xconnect service Gi3-9, group right
Associated member Gi3 is up, status is up
Interworking type is Like2Like
Service id: 0xcb000002
Signaling protocol: LDP, peer 192.0.2.1:0 up
Targeted Hello: 192.0.2.5(LDP Id) -> 192.0.2.1, LDP is UP
Graceful restart: not configured and not enabled
Non stop routing: not configured and not enabled
PWid FEC (128), VC ID: 1
Status TLV support (local/remote) : enabled/supported
LDP route watch : enabled
Label/status state machine : established, LruRru
Local dataplane status received : No fault
BFD dataplane status received : Not sent
BFD peer monitor status received : No fault
Status received from access circuit : No fault
Status sent to access circuit : No fault
Status received from pseudowire i/f : No fault
Status sent to network peer : No fault
Status received from network peer : No fault
Adjacency status of remote peer : No fault
Sequencing: receive disabled, send disabled
Bindings
Parameter Local Remote
------------ ------------------------------ ------------------------------
Label 48 69
Group ID n/a 0
Interface
MTU 1500 1500
Control word on (configured: autosense) on
PW type Ethernet Ethernet
VCCV CV type 0x02 0x02
LSPV [2] LSPV [2]
VCCV CC type 0x07 0x07
CW [1], RA [2], TTL [3] CW [1], RA [2], TTL [3]
Status TLV enabled supported
SSO Descriptor: 192.0.2.1/1, local label: 48
Dataplane:
SSM segment/switch IDs: 8199/4100 (used), PWID: 1
Rx Counters
2 input transit packets, 198 bytes
0 drops, 0 seq err
Tx Counters
79 output transit packets, 10387 bytes
0 drops
pseudowire100003 is up, VC status is standby PW type: Ethernet
Create time: 00:11:13, last status change time: 1w2d
Last label FSM state change time: 00:11:12
Destination address: 192.0.2.1 VC ID: 2
Output interface: Gi1, imposed label stack {16 71}
Preferred path: not configured
Default path: active
Next hop: 10.3.5.3
Member of xconnect service Gi3-9, group right
Associated member Gi3 is up, status is up
Interworking type is Like2Like
Service id: 0xcb000002
Signaling protocol: LDP, peer 192.0.2.1:0 up
Targeted Hello: 192.0.2.5(LDP Id) -> 192.0.2.1, LDP is UP
Graceful restart: not configured and not enabled
Non stop routing: not configured and not enabled
PWid FEC (128), VC ID: 2
Status TLV support (local/remote) : enabled/supported
LDP route watch : enabled
Label/status state machine : established, LrdRrd
Local dataplane status received : No fault
BFD dataplane status received : Not sent
BFD peer monitor status received : No fault
Status received from access circuit : DOWN(standby)
Status sent to access circuit : DOWN(standby)
Status received from pseudowire i/f : No fault
Status sent to network peer : DOWN(standby)
Status received from network peer : DOWN(standby)
Adjacency status of remote peer : No fault
Sequencing: receive disabled, send disabled
Bindings
Parameter Local Remote
------------ ------------------------------ ------------------------------
Label 49 71
Group ID n/a 0
Interface
MTU 1500 1500
Control word on (configured: autosense) on
PW type Ethernet Ethernet
VCCV CV type 0x02 0x02
LSPV [2] LSPV [2]
VCCV CC type 0x07 0x07
CW [1], RA [2], TTL [3] CW [1], RA [2], TTL [3]
Status TLV enabled supported
SSO Descriptor: 192.0.2.1/2, local label: 49
Dataplane:
SSM segment/switch IDs: 4102/8197 (used), PWID: 2
Rx Counters
0 input transit packets, 0 bytes
0 drops, 0 seq err
Tx Counters
0 output transit packets, 0 bytes
0 drops
CSR8#ping 10.100.1.18
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.100.1.18, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 18/36/55 ms
CSR5#show l2vpn atom vc detail | b Rx|Tx
Rx Counters
7 input transit packets, 878 bytes
0 drops, 0 seq err
Tx Counters
99 output transit packets, 12990 bytes
0 drops
CSR1
interface GigabitEthernet5
xconnect 192.0.2.5 1 encapsulation mpls
backup peer 192.0.2.5 2 priority 2
CSR5
interface GigabitEthernet3
xconnect 192.0.2.1 1 encapsulation mpls
backup peer 192.0.2.1 2 priority 2
CSR1#show xconnect peer 192.0.2.5 all detail
Legend: XC ST=Xconnect State S1=Segment1 State S2=Segment2 State
UP=Up DN=Down AD=Admin Down IA=Inactive
SB=Standby HS=Hot Standby RV=Recovering NH=No Hardware
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP pri ac Gi5:11(Ethernet) UP mpls 192.0.2.5:1 UP
Interworking: none Local VC label 69
Remote VC label 48
IA sec ac Gi5:11(Ethernet) UP mpls 192.0.2.5:2 SB
Interworking: none Local VC label 71
Remote VC label 49
CSR5#show xconnect peer 192.0.2.1 all detail
Legend: XC ST=Xconnect State S1=Segment1 State S2=Segment2 State
UP=Up DN=Down AD=Admin Down IA=Inactive
SB=Standby HS=Hot Standby RV=Recovering NH=No Hardware
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP pri ac Gi3:9(Ethernet) UP mpls 192.0.2.1:1 UP
Interworking: none Local VC label 48
Remote VC label 69
IA sec ac Gi3:9(Ethernet) UP mpls 192.0.2.1:2 SB
Interworking: none Local VC label 49
Remote VC label 71
CSR5#show l2vpn atom vc
Service
Interface Peer ID VC ID Type Name Status
--------- --------------- ---------- ------ ------------------------ ----------
pw100001 192.0.2.1 1 p2p Gi3-9 UP
pw100003 192.0.2.1 2 p2p Gi3-9 STANDBY
CSR5#show l2vpn atom vc detail
pseudowire100001 is up, VC status is up PW type: Ethernet
Create time: 00:11:13, last status change time: 00:11:13
Last label FSM state change time: 00:11:12
Destination address: 192.0.2.1 VC ID: 1
Output interface: Gi1, imposed label stack {16 69}
Preferred path: not configured
Default path: active
Next hop: 10.3.5.3
Member of xconnect service Gi3-9, group right
Associated member Gi3 is up, status is up
Interworking type is Like2Like
Service id: 0xcb000002
Signaling protocol: LDP, peer 192.0.2.1:0 up
Targeted Hello: 192.0.2.5(LDP Id) -> 192.0.2.1, LDP is UP
Graceful restart: not configured and not enabled
Non stop routing: not configured and not enabled
PWid FEC (128), VC ID: 1
Status TLV support (local/remote) : enabled/supported
LDP route watch : enabled
Label/status state machine : established, LruRru
Local dataplane status received : No fault
BFD dataplane status received : Not sent
BFD peer monitor status received : No fault
Status received from access circuit : No fault
Status sent to access circuit : No fault
Status received from pseudowire i/f : No fault
Status sent to network peer : No fault
Status received from network peer : No fault
Adjacency status of remote peer : No fault
Sequencing: receive disabled, send disabled
Bindings
Parameter Local Remote
------------ ------------------------------ ------------------------------
Label 48 69
Group ID n/a 0
Interface
MTU 1500 1500
Control word on (configured: autosense) on
PW type Ethernet Ethernet
VCCV CV type 0x02 0x02
LSPV [2] LSPV [2]
VCCV CC type 0x07 0x07
CW [1], RA [2], TTL [3] CW [1], RA [2], TTL [3]
Status TLV enabled supported
SSO Descriptor: 192.0.2.1/1, local label: 48
Dataplane:
SSM segment/switch IDs: 8199/4100 (used), PWID: 1
Rx Counters
2 input transit packets, 198 bytes
0 drops, 0 seq err
Tx Counters
79 output transit packets, 10387 bytes
0 drops
pseudowire100003 is up, VC status is standby PW type: Ethernet
Create time: 00:11:13, last status change time: 1w2d
Last label FSM state change time: 00:11:12
Destination address: 192.0.2.1 VC ID: 2
Output interface: Gi1, imposed label stack {16 71}
Preferred path: not configured
Default path: active
Next hop: 10.3.5.3
Member of xconnect service Gi3-9, group right
Associated member Gi3 is up, status is up
Interworking type is Like2Like
Service id: 0xcb000002
Signaling protocol: LDP, peer 192.0.2.1:0 up
Targeted Hello: 192.0.2.5(LDP Id) -> 192.0.2.1, LDP is UP
Graceful restart: not configured and not enabled
Non stop routing: not configured and not enabled
PWid FEC (128), VC ID: 2
Status TLV support (local/remote) : enabled/supported
LDP route watch : enabled
Label/status state machine : established, LrdRrd
Local dataplane status received : No fault
BFD dataplane status received : Not sent
BFD peer monitor status received : No fault
Status received from access circuit : DOWN(standby)
Status sent to access circuit : DOWN(standby)
Status received from pseudowire i/f : No fault
Status sent to network peer : DOWN(standby)
Status received from network peer : DOWN(standby)
Adjacency status of remote peer : No fault
Sequencing: receive disabled, send disabled
Bindings
Parameter Local Remote
------------ ------------------------------ ------------------------------
Label 49 71
Group ID n/a 0
Interface
MTU 1500 1500
Control word on (configured: autosense) on
PW type Ethernet Ethernet
VCCV CV type 0x02 0x02
LSPV [2] LSPV [2]
VCCV CC type 0x07 0x07
CW [1], RA [2], TTL [3] CW [1], RA [2], TTL [3]
Status TLV enabled supported
SSO Descriptor: 192.0.2.1/2, local label: 49
Dataplane:
SSM segment/switch IDs: 4102/8197 (used), PWID: 2
Rx Counters
0 input transit packets, 0 bytes
0 drops, 0 seq err
Tx Counters
0 output transit packets, 0 bytes
0 drops
CSR8#ping 10.100.1.18
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.100.1.18, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 18/36/55 ms
CSR5#show l2vpn atom vc detail | b Rx|Tx
Rx Counters
7 input transit packets, 878 bytes
0 drops, 0 seq err
Tx Counters
99 output transit packets, 12990 bytes
0 drops