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[EX] MC-LAG Support on EX4300 deprecated starting 17.4R1 release



Article ID: KB35466 KB Last Updated: 26 Aug 2020Version: 2.0

This article clarifies that MC-LAG support on EX4300 Series switches has been deprecated starting with Junos OS Release 17.4R1, and suggests an alternative.



Although the configuration commit will go through, the settings will not take effect. Help and auto-completion will not also happen.

Additionally, platform exclusion warning would be seen on this configuration hierarchy, as shown below:

{master:0}[edit protocols]
root@nj-cnt-jnpr-sw-4300# show
## Warning: configuration block ignored: unsupported platform (ex4300-24t)
iccp {
    peer {
        session-establishment-hold-time 400;
        redundancy-group-id-list 1;
        backup-liveness-detection {
        liveness-detection {
            minimum-interval 2000;
            multiplier 4;
        authentication-key "$9$bRY4JTQ39CpcyML"; ## SECRET-DATA

{master:0}[edit interfaces ae2]
root@nj-cnt-jnpr-sw-4300# show
aggregated-ether-options {
    lacp {
        periodic slow;
        system-id 00:00:00:00:00:02;
        admin-key 2;
    ## Warning: configuration block ignored: unsupported platform (ex4300-24t)
    mc-ae {
        mc-ae-id 2;
        ## Warning: The redundancy group must match with one defined at <protocols iccp peer redundancy-group-id-list>
        redundancy-group 1;
        chassis-id 0;
        mode active-active;
        status-control active;
        init-delay-time 300;
        events {
            iccp-peer-down {
unit 0 {
    family ethernet-switching {
        interface-mode trunk;
        vlan {
            members [ v10 v11 v12 ];



The MC-LAG feature was introduced on the EX4300 platform running Junos OS Release 13.2X51-D20.

This feature is deprecated starting Junos OS 17.4R1 and later releases.

For details, check the Feature Explorer for MC-LAG.



Consider using a Virtual Chassis or, alternatively, all-active multihoming for EVPN-VXLAN (ESI-LAG aka EVPN-LAG). All-active multihoming for EVPN-VXLAN (ESI-LAG aka EVPN-LAG) is supported on the EX4300 Multigigabit EX4300-48MP platform from Junos OS Release 19.1R1.

However, be sure to check the Feature Explorer for All-active multihoming support for EVPN-VXLAN (ESI-LAG aka EVPN-LAG)‚Äč before configuring the above.

Note: Some VXLAN constraints on the switching platform that you may want to consider can be found in VXLAN Constraints on QFX Series and EX Series Switches.


Modification History:
2020-08-26: Minor, non-technical edit.

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