Multiple VLAN Registration Protocol (MVRP) is a Layer 2 messaging protocol that automates the creation and management of virtual LANs, thereby reducing the time you have to spend on these tasks. If your QFabric system connects to servers that host many virtual machines that require their own VLANs, using MVRP can save you the time and effort that would be required to manually create and administer the VLANs on the ports that connect to the servers. For example, if a virtual machine moves between servers—and therefore connects to a different redundant server Node group interface—MVRP can configure the appropriate VLAN membership on the new server Node group interface.

When using MVRP on a QFabric system, you must manually create on the QFabric the VLANs that exist on the attached servers because the QFabric implementation of MVRP does not allow VLANs to be created dynamically. However, you do not need to manually assign VLAN membership to the QFabric ports that connect to the servers. MVRP automatically assigns VLAN membership to server-facing QFabric ports when it learns about a VLAN from an attached server.

MVRP is an application protocol of the Multiple Registration Protocol (MRP) and is defined in the IEEE 802.1ak standard. MRP and MVRP replace Generic Attribute Registration Protocol (GARP) and GARP VLAN Registration Protocol (GVRP) and overcome GARP and GVRP limitations.

Note: MVRP on QFabric systems does not support private VLANs.

QFabric Requirements

When configuring MVRP on a QFabric system, you can enable it globally or enable it only on the trunk ports that need to carry VLAN traffic from the attached servers. You also must manually create the expected VLANs, but you do not have to assign VLAN membership to the server-facing redundant server Node ports (as mentioned previously). However, you do have to manually assign VLAN membership to the uplink ports on the redundant server Node group and network Node group devices that will carry the VLAN traffic. Table 1 summarizes the VLAN requirements for redundant server Node groups and network Node groups:

MVRP Operations

MVRP stays synchronized by using MVRP protocol data units (PDUs). These PDUs specify which QFabric systems and switches are members of which VLANs, and which switch interfaces are in each VLAN. The MVRP PDUs are sent to other switches in the QFabric system when an MVRP state change occurs, and the receiving switches update their MVRP states accordingly. MVRP timers dictate when PDUs can be sent and when switches receiving MVRP PDUs can update their MVRP information.

In addition to this behavior, QFX switches include a mode—called passive mode—in which an MVRP-configured interface does not announce its membership in a VLAN or send any VLAN declarations (updates) unless it receives registration for that VLAN from a peer (server) on that interface. By default MVRP-configured interfaces behave in the standard manner and automatically send PDU updates to announce any VLAN changes. (This is called active mode.)

To enable passive mode on an interface, enter and commit this statement:

To keep VLAN membership information current, MVRP removes switches and interfaces when they become unavailable. Pruning VLAN information has these benefits:

• Limits the network VLAN configuration to active participants, thereby reducing network overhead.
• Limits broadcast, unknown unicast, and multicast (BUM) traffic to interested devices.

MVRP is disabled by default and is valid only for trunk interfaces.

MRP Timers Control MVRP Updates

MVRP registration and updates are controlled by timers that are part of MRP. The timers define when MVRP PDUs can be sent and when MVRP information can be updated. You configure the timers on a per-interface basis.

The following MRP timers are used to control the operation of MVRP:

• Join timer—Controls the interval for the next MVRP PDU transmit opportunity.
• Leave timer—Controls the period of time that an interface on the switch waits in the leave state before changing to the unregistered state.
• LeaveAll timer—Controls the frequency with which the interface generates LeaveAll messages.

Best Practice: Unless there is a compelling reason to change the timer settings, leave the default settings in place. Modifying timers to inappropriate values can cause an imbalance in the operation of MVRP.

MVRP Uses MRP Messages to Transmit Switch and VLAN States

MVRP uses MRP messages to register and declare MVRP states for a interface or VLAN and to inform the switching network that a interface or VLAN is leaving MVRP. These messages are communicated in the MRP PDUs sent by MVRP-enabled interfaces.

The following MRP messages are communicated for MVRP:

• Empty—MVRP information is not declared and no VLAN is registered.
• In—MVRP information is not declared but a VLAN is registered.
• JoinEmpty—MVRP information is declared but no VLAN is registered.
• JoinIn—MVRP information is declared and a VLAN is registered.
• Leave—MVRP information that was previously declared is withdrawn.
• LeaveAll—Unregister all VLANs on the switch. VLANs must re-register to participate in MVRP.
• New—The MVRP information is new and a VLAN might not be registered yet.