C H A P T E R
6
MAC Limiting
This document describes how to configure MAC limiting.
•
Restrictions and Usage Guidelines, page 75
•
Configuring MAC Limiting, page 75
Restrictions and Usage Guidelines
MAC limiting is supported on the following interface types:
•
You can apply MAC limiting only to bridge-domains.
•
MAC limiting is supported for dynamic MAC addresses.
Configuring MAC Limiting
Mac address limiting per bridge-domain restricts the number of MAC addresses that the router learns in
bridge-domain on an EFP, pseudowire or switchport.
Local connect feature is not supported on the Cisco router. However, to simulate a local connect scenario,
configure the connecting EFPs on the same bridge domain and disable the mac-learning on the bridge
domain by setting the MAC limit to 0. Use the
mac-address-table limit bdomain num maximum 0
action limit
command to disable mac-learning on the router.
Note
When the total number of addresses in a bridge-domain exceeds the maximum number, the router takes a
violation action. You can enable the following actions:
•
Warning
—
The router sends a syslog message and takes no further action. The router continues learning
new MAC addresses and forwarding traffic.
•
Limit
—
The router sends a syslog message and generates a trap; MAC learning is disabled on the
bridge-domain until the recovery mechanism activates. Flooding of frames with new MAC addresses
continues; to disable flooding, use the flood keyword. Flooding continues once the total number of MAC
entries drops below the threshold value. This option applies only when you configure the limit keyword.
Layer 2 Configuration Guide for Cisco NCS 4200 Series
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