Chapter 89 Configuring Rate Limiting; Configuring Unknown Unicast Forwarding (Cli Procedure) - Juniper JUNOS OS 10.3 - SOFTWARE Manual

CHAPTER 89
Configuring Rate Limiting

Configuring Unknown Unicast Forwarding (CLI Procedure)

Related
Documentation
Copyright © 2010, Juniper Networks, Inc.
Configuring Unknown Unicast Forwarding (CLI Procedure) on page 2795
Configuring Autorecovery From the Disabled State on Secure or Storm Control Interfaces
(CLI Procedure) on page 2796
Unknown unicast traffic consists of packets with unknown destination MAC addresses.
By default, the switch floods these packets to all interfaces associated with a VLAN.
Forwarding such traffic to interfaces on the switch can create a security issue.
To prevent flooding unknown unicast traffic across the switch, configure unknown unicast
forwarding to direct all unknown unicast packets within a VLAN out to a specific trunk
interface. From there, the destination MAC address can be learned and added to the
Ethernet switching table. You can configure each VLAN to divert unknown unicast traffic
to different trunk interfaces or use one trunk interface for multiple VLANs.
To configure unknown unicast forwarding options using the CLI:
NOTE: Before you can configure unknown unicast forwarding within a VLAN,
you must first configure that VLAN.
Configure unknown unicast forwarding for a specific VLAN (here, the VLAN name is
1.
):
employee
[edit ethernet-switching-options]
user@switch# set unknown-unicast-forwarding vlan employee
Specify the trunk interface to which all unknown unicast traffic will be forwarded:
2.
[edit ethernet-switching-options ]
user@switch# set unknown-unicast-forwarding vlan employee interface ge-0/0/3.0
Example: Configuring Storm Control to Prevent Network Outages on EX Series Switches
on page 2793
Configuring VLANs for EX Series Switches (CLI Procedure) on page 1378
Configuring VLANs for EX Series Switches (J-Web Procedure) on page 1375
2795