MRP messages

MRP messages include the following types:

• Declaration—Includes Join and New messages.

• Withdrawal—Includes Leave and LeaveAll messages.

An MRP participant sends a Join message to request the peer participant to register attributes in the Join message.

When receiving a Join message from the peer participant, an MRP participant performs the following tasks:

• Registers the attributes in the Join message.

• Propagates the Join message to all other participants on the device.

After receiving the Join message, other participants send the Join message to their respective peer participants.

Join messages sent from a local participant to its peer participant include the following types:

• JoinEmpty—Declares an unregistered attribute. For example, when an MRP participant joins an unregistered static VLAN, it sends a JoinEmpty message.

  VLANs created manually and locally are called static VLANs. VLANs learned through MRP are called dynamic VLANs.

• JoinIn—Declares a registered attribute. A JoinIn message is used in one of the following situations:

  • An MRP participant joins an existing static VLAN and sends a JoinIn message after registering the VLAN.

  • The MRP participant receives a Join message propagated by another participant on the device and sends a JoinIn message after registering the VLAN.

Similar to a Join message, a New message enables MRP participants to register attributes.

When the MSTP topology changes, an MRP participant sends a New message to the peer participant to declare the topology change.

Upon receiving a New message from the peer participant, an MRP participant performs the following tasks:

• Registers the attributes in the message.

• Propagates the New message to all other participants on the device.

After receiving the New message, other participants send the New message to their respective peer participants.

An MRP participant sends a Leave message to the peer participant when it wants the peer participant to deregister attributes that it has deregistered.

When the peer participant receives the Leave message, it performs the following tasks:

• Deregisters the attribute in the Leave message.

• Propagates the Leave message to all other participants on the device.

After a participant on the device receives the Leave message, it determines whether to send the Leave message to its peer participant depending on the attribute status on the device.

• If the VLAN in the Leave message is a dynamic VLAN not registered by any participants on the device, both of the following events occur:

  • The VLAN is deleted on the device.

  • The participant sends the Leave message to its peer participant.

• If the VLAN in the a Leave message is a static VLAN, the participant will not send the Leave message to its peer participant.

Each MRP participant starts its LeaveAll timer when starting up. When the timer expires, the MRP participant sends LeaveAll messages to the peer participant.

Upon sending or receiving a LeaveAll message, the local participant starts the Leave timer. The local participant determines whether to send a Join message depending on its the attribute status. A participant can re-register the attributes in the received Join message before the Leave timer expires.

When the Leave timer expires, a participant deregisters all attributes that have not been re-registered to periodically clear useless attributes in the network.