When interface-mac-limit is enabled on the EX2300 and EX3400 Series of devices, the device interface stops forwarding traffic and the connected equipment's MAC address does not show in the MAC table of the respective device. This article gives the reason and a suggested workaround.

The device interface stops forwarding traffic, leading to blocked traffic on that source, and the connected equipment's MAC address does not show in the MAC table of the device.

When the following command is run in shell mode, the MAC address may show a Hit Pending state on some interfaces:

% cprod -A fpc0 -c 'set dc bc "l2 show"' | egrep -i          Pending
mac=00:e0:4c:68:01:5a vlan=4 GPORT=0xd modid=0 port=13/ge11  Hit Pending
mac=ec:a8:6b:a8:0d:2c vlan=4 GPORT=0x5 modid=0 port=5/ge3    Hit Pending
mac=ec:a8:6b:a8:40:b8 vlan=4 GPORT=0x18 modid=0 port=24/ge22 Hit Pending
mac=c8:9c:dc:28:52:4d vlan=4 GPORT=0x9 modid=0 port=9/ge7    Hit Pending

This is because the EX2300-VC and EX3400-VC stop learning the MAC address for a particular interface when interface-mac-limit is enabled.

This issue is resolved in PR1341518 - A MAC address might not be learned and display as "Hit Pending" status

Meanwhile, the workaround for this issue is to disable interface-mac-limit as follows:

[edit switch-options]
user@switch# delete interface interface-name interface-mac-limit limit packet-action action

2020-08-04: Article reviewed for accuracy. No changes required. Article is correct and complete.