Pseudowire Group Message Generation
The Pseudowire Group Message Generation feature assigns the pseudowire group ID for a group of pseudowires and sends wildcard status notifications or label withdrawal messages for a group.
Prerequisites for Pseudowire Group Message Generation
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The remote provider edge (PE) router must be capable of receiving group status messages.
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Label Distribution Protocol (LDP) must be implemented on the network.
Restrictions for Pseudowire Group Message Generation
The Pseudowire Group Message Generation feature is supported on Cisco IOS XE Release 3.16 and later releases.
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This feature is supported on Cisco Routers on the following attachment circuits:
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Ethernet VLAN
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Asynchronous Transfer Mode (ATM)
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Circuit Emulation over MPLS (CEM)
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Pseudowire group ID is unique and is assigned automatically.
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This feature can only be configured globally rather than for each xconnect.
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Hot Standby Pseudowire (HSPW) has high convergence for Cisco RSP3 Module.
Information About Pseudowire Group Message Generation
The pseudowires associated with a given attachment circuit parent (e.g. physical or port channel) interface are grouped together by assigning a group ID. The group ID is assigned based on port index or virtual tunnel index of the interface. When a fault occurs in a group of pseudowires, a single status message is sent to the remote PE router for that particular group ID. When the status message is received by the remote PE router, it can switch the entire group to the designated backup pseudowires, instead of switching an individual pseudowire, thus reducing switchover time.
The Pseudowire Group Message Generation feature thus enhances recovery performance and scalability by reducing switchover time.
 Note |
The Pseudowire Group Message Generation feature is disabled by default. |
Multisegment Pseudowire
An L2VPN multisegment pseudowire (MS-PW) is a set of two or more PW segments that function as a single PW. When a MS-PW is configured, the switching provider edge router (S-PE) assigns Local group IDs to each pseudowire. This group ID is then sent to the terminating provider edge routers (T-PEs). Pseudowire group status messages received from a T-PE are then converted into group status messages for another T-PE by using the locally assigned group ID to prevent replication of group IDs.
Configuring Pseudowire Group Message Generation
Procedure
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
| Step 2 |
configure terminal Example: |
Enters global configuration mode. |
| Step 3 |
l2vpn Example: |
Enters l2vpn configuration mode. |
| Step 4 |
pseudowire group status Example: |
Sends pseudowire group status messages. |
| Step 5 |
end Example: |
Exits l2vpn configuration mode and returns to privileged EXEC mode. |
Example for Configuring Pseudowire Group Message
The following example shows how to configure a pseudowire group message:
PE1:
Router# show run interface GigabitEthernet0/3/5
Building configuration...
Current configuration: 1623 bytes
!
interface GigabitEthernet0/3/5
mtu 1504
no ip address
carrier-delay msec 0
negotiation auto
service instance 100 ethernet
encapsulation dot1q 100
xconnect 2.2.2.2 1000 encapsulation mpls
backup peer 3.3.3.3 1000
backup delay 0 40
PE2:
Router# show run | section l2vpn
l2vpn
logging pseudowire status
pseudowire group status
Verifying a Pseudowire Group Message Configuration
You can use show commands to view information about a pseudowire group message configuration.
The following example displays the information about local pseudowire groups and the parent interface state the last time when the pseudowire status was sent:
Device# show l2vpn atom group local
Peer Address Group ID Status
------------- ---------- ---------
1.1.1.1 5 UP
The following example displays the count of the number of LDP messages sent and received:
Device# show l2vpn atom statistics ldp
Load for five secs: 0%/0%; one minute: 0%; five minutes: 0%
Time source is hardware calendar, *07:36:32.858 PST Wed Dec 10 2014
LDP Message Type Sent Received
------------------ ----------- ----------
Label Mapping 10 10
Label Request 0 0
Label Release 0 0
Label Withdraw 0 0
Group Withdraw 0 0
VC Notification 55 20
Group Notification 0 1
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