Restrictions And Usage Guidelines - Cisco NCS 4200 Series Configuration Manual

MAC Limiting
This document describes how to configure MAC limiting.
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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,
Note
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.
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
• Limit—The router sends a syslog message and generates a trap; MAC learning is disabled on the
Restrictions and Usage Guidelines, page 75
Configuring MAC Limiting, page 75
new MAC addresses and forwarding traffic.
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.
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Layer 2 Configuration Guide for Cisco NCS 4200 Series
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