This article provides a workaround when ARP entries related to a certain VLAN/IRB are no longer appearing after a power outage or power cycle.

In this scenario, the switch suffered from power outage on site, and ever since then the ARP entries related to one of the VLAN/IRB are no longer appearing.

A good workaround might be deleting the configuration related to the IRB in question followed by re-configuring the same with commits between deletion and re-configuration.

Deleting all config related to irb.101:

user@switch# delete interfaces irb.101
user@switch# delete vlans VLAN101 l3-interfaces irb.101
user@switch# commit

Re-configuring:

user@switch# set interfaces irb.101 family inet address 192.168.0.1/24
user@switch# set vlans VLAN101 l3-interfaces irb.101
user@switch# commit

Note: It is worth taking into account that sudden power loss with no system services halting, may cause file system inconsistencies or file system corruption. This could be a potential cause of this behavior. If the issue persists or the switch presents more strange issues which do not have another explanation from root cause analysis done by Juniper TAC team, you may be suggested to proceed with USB format installation for file system re-installation.