Negotiating the Primary/Secondary Status of a PW

Context

In the Independent PW redundancy scenario where CEs are asymmetrically connected to PEs, the primary/secondary status of a local PE is determined by the signaling status of the remote PE and the primary/secondary status of AC-side links is determined by E-Trunk.

To negotiate the primary/secondary status of a PW, configure Eth-Trunk and E-Trunk and bind BFD sessions to an E-Trunk to accelerate fault detection on the AC-side links.

This section describes basic configurations of Eth-Trunk and E-Trunk. For detailed configurations of Eth-Trunk, see Configuring Link Aggregation in LACP Mode in "Link Aggregation Configuration" in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - Ethernet Switching. For details about E-Trunk and binding between BFD and E-Trunk, see Configuring an E-Trunk in "Link Aggregation Configuration" in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - Ethernet Switching.

Procedure

Configure an Eth-Trunk.
Perform the following operations on a CE and PEs to which the CE is dual-homed.
1. Run system-view
  The system view is displayed.
2. Run interface eth-trunk trunk-id
  An Eth-Trunk is created.
3. (Optional) Run portswitch
  The Eth-Trunk interface is switched from the Layer 3 mode to the Layer 2 mode.
  
  Only the Eth-Trunk interface on the CE needs to be switched from the Layer 3 mode to the Layer 2 mode. The Eth-Trunk sub-interface on a PE serves as the AC interface for a service PW.
4. Run mode lacp
  The Eth-Trunk interface is configured to work in static LACP mode.
  
  By default, an Eth-Trunk interface works in manual load balancing mode.
5. (Optional) Run port trunk allow-pass vlan { { vlan-id1 [ to vlan-id2 ] } &<1-10> | all }
  The Eth-Trunk interface is configured to allow packets with specified tags to pass through.
  
  Perform this configuration only on the CE where a VLAN needs to be configured.
6. Run trunkport interface-type interface-number
  A member interface is added to the Eth-Trunk.
  
  On the CE, two interfaces connecting to the PEs need to be added to the Eth-Trunk.
  
  On each PE, only the interface connecting to the CE needs to be added to the Eth-Trunk.
7. Run quit
  Return to the system view.
Configure an E-Trunk.
Perform the following operations on the PEs to which the CE is dual-homed.
1. Run lacp e-trunk system-id mac-address
  An LACP system ID is configured for the E-Trunk.
  
  By default, the MAC address of Ethernet interface on the master device is used as the LACP system ID of the E-Trunk.
  
  The master and backup devices in an E-Trunk must use the same LACP system ID.
2. Run lacp e-trunk priority priority
  The LACP priority is configured for the E-Trunk.
  
  By default, the LACP priority of an E-Trunk is 32768. A smaller value indicates a higher priority.
  
  The master and backup devices in an E-Trunk must use the same LACP priority.
3. Run e-trunk e-trunk-id
  An E-Trunk is created.
4. Run priority priority
  A priority is configured for the E-Trunk.
  
  By default, the priority of an E-Trunk is 100. A smaller value indicates a higher priority.
5. Run peer-address peer-ip-address source-address source-ip-address
  Local and remote IP addresses are configured for the E-Trunk.
6. Run quit
  Return to the system view.
7. Run interface eth-trunk trunk-id
  The Eth-Trunk interface view is displayed.
8. Run e-trunk e-trunk-id
  An Eth-Trunk interface is added to a specified E-Trunk.
9. Run quit
  Return to the system view.
Bind BFD to the E-Trunk.
Perform the following operations on the PEs to which the CE is dual-homed.
1. Run bfd bfd-name bind peer-ip peer-ip [ interface interface-type interface-number ] [ source-ip source-ip ]
  A BFD session is created.
  
  The IP addresses of the local and remote ends of a BFD session must be the same as those of the E-Trunk.
2. Run discriminator local discr-value
  A local discriminator is configured.
3. Run discriminator remote discr-value
  A remote discriminator is configured.
  
  The local discriminator of the local device must be the same as the remote discriminator of the remote device; the remote discriminator of the local device must be the same as the local discriminator of the remote device. Otherwise, BFD sessions cannot be established. After the local and remote discriminators are configured, you cannot modify them.
4. Run commit
  The configuration is committed.
5. Run quit
  Return to the system view.
6. Run e-trunk e-trunk-id
  The E-Trunk view is displayed.
7. Run e-trunk track bfd-session session-name bfd-session-name
  A BFD session is bound to the E-Trunk.