Ethernet Switching on EX Series Switches - Juniper Networks

<strong>Ethernet</strong> <strong>Switching</strong> on EX Series Switches
(the default normal mode) and those interfaces accept PDU messages and send their
own PDU messages. To prevent one or more interfaces from participating in MVRP, you
can specifically configure an interface to forbidden mode instead of the default normal
mode.
MRP Timers Control MVRP Updates
VLAN updating, dynamic VLAN configuration through MVRP, and VLAN pruning are all
active on trunk interfaces when MVRP is enabled.
MVRP registration and updates are controlled by timers that are part of the MRP. These
timers are set on a per-interface basis and define when MVRP PDUs can be sent and
when MVRP information can be updated on a switch.
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
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MVRP uses MRP messages to register and declare MVRP states for a switch or VLAN
and to inform the switching network that a switch or VLAN is leaving MVRP. These
messages are communicated as part of the PDU sent by any switch interface to the other
switches in the network.
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• Leave—MVRP information that was previously declared is withdrawn.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.
Copyright © 2012, Juniper Networks, Inc.