This article explains the interface order of JA2500 appliance from 21.1 version.

Interface order of JA2500 appliance from 21.1 version.

After upgrading  the Junos space (JA2500) to 21.1 the default gateway will not be reachable.

Starting in Junos Space Network Management Platform Release 21.1R1, Ethernet interface order is changed for the JA2500 Junos Space Appliance.

Physical Ethernet connection in the JA2500 appliance needs to be altered as below:

1. Cable in eth0 needs to be connected to eth3 port that is as per notations on the JA2500 appliance front panel 3.
2. Cable in eth1 needs to be connected to eth2 port that is as per notations on the JA2500 appliance front panel 2.
3. Cable in eth2 needs to be connected to eth1 port that is as per notations on the JA2500 appliance front panel 1.
4. Cable in eth3 needs to be connected to eth0 port that is as per notations on the JA2500 appliance front panel 0.

 If you need any assistance please contact JTAC.

2025-04-08 : Article Created

2025-12-09 : Minor change and visibility changed.

https://www.juniper.net/documentation/us/en/hardware/ja2500/topics/concept/junos-space-appliance-ethernet-interfaces-overview.html