Description

This article explains issues with the minimum-links configuration on aggregate link-speed mixed interfaces and provides alternative solutions for implementation. 

Symptoms

When using minimum-links knob with aggregate interfaces that have mixed speeds, a commit error will occur. This is because minimum-links is not compatible with mixed-speed interfaces by design.

 

set interfaces ae1 mtu 9216
set interfaces ae1 aggregated-ether-options link-speed mixed
set interfaces ae1 aggregated-ether-options lacp active
set interfaces ae1 unit 0 family inet address 1.1.1.1/30
set interfaces ae1 unit 0 family iso
set interfaces ae1 unit 0 family mpls

 

[edit]

labroot@MX# set interfaces ae1 aggregated-ether-options minimum-links 2 

 

[edit]

labroot@MX# commit 

[edit interfaces ae1 aggregated-ether-options minimum-links]

 'minimum-links 2'

  Minimum-links option is not compatible with link-speed mixed

error: commit failed: (statements constraint check failed)

 

 

Solution

As a solution, implement minimum-bandwidth knob with mixed-speed as per your use case. For the below use case, two 100G member links are part of the aggregate interface, with each member link on a different FPC. 

 

labroot@MX1# set interfaces ae1 aggregated-ether-options minimum-bandwidth bw-value 200 bw-unit gbps

 

labroot@MX1# run show interfaces ae1

Physical interface: ae1, Enabled, Physical link is Up

 Interface index: 131, SNMP ifIndex: 659

 Description: P2P_C_B ae1 Bundle toward MDCI02.BLOOR port ae1

 Link-level type: Ethernet, MTU: 9216, Speed: 200Gbps, BPDU Error: None, MAC-REWRITE Error: None, Loopback: Disabled,

 

 

labroot@MX1> request chassis fpc slot 0 offline

 

 

labroot@MX1> show interfaces ae1 

Physical interface: ae1, Enabled, Physical link is Down

 Interface index: 131, SNMP ifIndex: 659

 Description: P2P_C_B ae1 Bundle toward MDCI02.BLOOR port ae1

 Link-level type: Ethernet, MTU: 9216, Speed: 100Gbps, BPDU Error: None, MAC-REWRITE Error: None, Loopback: Disabled,

Modification History

2025-04-28 : Article Created

2026-06-15 : Mark to be external

Related Information

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/minimum-bandwidth-edit-interfaces.html