local-minimum-links-threshold

Syntax

Hierarchy Level

Description

For an aggregated Ethernet interface (LAG bundle) with member links spanning multiple chassis (member switches) in a Virtual Chassis or Virtual Chassis Fabric (VCF), set a threshold for the percentage of member links local to any particular chassis that must be up for that chassis to continue to be active in the aggregated Ethernet bundle.

You configure a threshold for a particular aggregated Ethernet interface (aex). When set, the threshold applies locally to any chassis with links in the specified LAG bundle. The threshold value represents a percentage of active local member links out of the total number of local member links for the chassis. When one or more member links on a chassis go down, the system compares the percentage of local member links that are “up” to the threshold. If the percentage of local member links that are “up” is less than the threshold, any remaining active local links are forced down as well, to prevent forwarding traffic for the aggregated Ethernet interface through any member links on that chassis. If the percentage of “up” links is greater than or equal to the threshold, the status of the active links remains unchanged and they can forward LAG traffic.

For example, consider a case where the threshold is set to 52, and one local LAG member link goes down on one switch in a Virtual Chassis Fabric that has a total of four local LAG member links. In this case, 75 percent of the links are still up (greater than the threshold, 52 percent), so the remaining local member links stay up. However, if two local member links go down, only 50 percent of the links are up, so the local minimum links feature forces the remaining two active local member links down as well.

This feature also adjusts local member link status accordingly when failed links come up again, if you reconfigure the threshold value, or if you add or remove local member links in the LAG bundle.

The local minimum links feature helps avoid traffic loss due to asymmetric bandwidth on the forwarding paths across a chassis when some local aggregated Ethernet member links fail and some remain active. Enable this feature only if you want to closely manage ingress and egress traffic forwarding paths on aggregated Ethernet interfaces, especially where local link bias is also enabled.

Default

The local minimum links feature is disabled by default.

Options

threshold-value—Percentage of member links in an aggregated Ethernet bundle local to a chassis that must be up for any local member links on that chassis to be active in the aggregated Ethernet bundle.

• Range: 1 through 100 (decimal)

• Default: none—This option is not enabled by default.

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 14.1X53-D40.