peer mac-limit (BGP-EVPN address family view) (ipv6)

Function

The peer mac-limit command configures the maximum number of MAC advertisement routes allowed to be received from a peer.

The undo peer mac-limit command restores the default configuration.

By default, the number of MAC advertisement routes allowed to be received from a peer is not limited.

Format

peer peerIpv6Addr mac-limit limit [ percentage ] [ alert-only | idle-forever | idle-timeout times ]

undo peer peerIpv6Addr mac-limit

Parameters

Parameter	Description	Value
peerIpv6Addr	Specifies the IPv6 address of a peer.	The value is a 32-digit hexadecimal number, in the format of X:X:X:X:X:X:X:X.
limit	Specifies the maximum number of MAC advertisement routes allowed to be received from a peer.	The value is an integer ranging from 1 to 4294967295.
percentage	Specifies a percentage of MAC advertisement routes for the device to generate an alarm. If the number of MAC advertisement routes received from a peer exceeds (number*percentage)/100, the device generates an alarm.	The value is an integer ranging from 1 to 100. The default value is 75.
alert-only	Indicates that an alarm will be generated and additional routes will be denied if the maximum number of routes allowed have been received. This parameter is recommended to prevent a peer disconnection when the number of routes received by the device exceeds the maximum limit.	-
idle-forever	Indicates that a connection that is interrupted after the maximum number of routes allowed have been received cannot be automatically re-established.	-
idle-timeout times	Specifies a timer for re-establishing a connection if the connection is interrupted after the maximum number of routes allowed have been received. Before the timer expires, the system does not re-establish a connection.	The value is an integer ranging from 1 to 1200, in minutes.

Views

BGP-EVPN address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

If an EVPN instance may import many invalid MAC advertisement routes from peers and these routes occupy a large proportion of the total number of MAC advertisement routes, run the peer mac-limit command to configure the maximum number of MAC advertisement routes allowed to be received from each peer. If the number of received MAC advertisement routes exceeds the specified maximum number, the system displays an alarm, instructing users to check the validity of the MAC advertisement routes received in the EVPN instance.

Configuration Impact

After this command is run, excess route prefixes of the EVPN instance may be discarded.

If the undo peer mac-limit command is run after the received MAC advertisement routes exceed the specified maximum number, the system receives route prefixes from PEs again to construct the BGP EVPN routing table.

If a peer relationship between two devices is in the Established state, the following situations occur:

If the number of routes received by the device exceeds the maximum limit after you run the peer mac-limit command for the first time or run the command to reduce the maximum limit:
If you specified alert-only in the command, the device does not disconnect its BGP peer. The received routes are not removed, and no additional routes will be accepted.
If you specified idle-forever in the command, the device disconnects its BGP peer. To re-establish the connection, run the reset bgp command.
If you specified idle-timeout in the command, the device disconnects its BGP peer and re-establishes its BGP peer relationship automatically after the timeout timer expires. To re-establish the connection before the timeout timer expires, run the reset bgp command.
If the upper limit set on the device is increased to be greater than the number of received routes, the device sends Refresh packets to receive routes again. If the device does not support the route-refresh capability, the device needs to re-establish the connection with its peer.
If the upper limit set on the device is reduced but is still greater than the number of received routes, only configuration parameters need to be modified.
Assume that none of alert-only, idle-forever, and idle-timeout is configured. If the number of routes exceeds the upper limit, an alarm is generated and recorded in the log. Then, the peer relationship is disconnected. The devices try to re-establish the peer relationship after 30 seconds.

Example

# Configure a device only to generate an alarm when more than 1000 MAC advertisement routes are received.

<HUAWEI> system-view
[~HUAWEI] bgp 100
[*HUAWEI-bgp] peer 2001:DB8:2::2 as-number 100
[*HUAWEI-bgp] l2vpn-family evpn
[*HUAWEI-bgp-af-evpn] peer 2001:DB8:2::2 enable
[*HUAWEI-bgp-af-evpn] peer 2001:DB8:2::2 mac-limit 1000 alert-only