Hi,

Interface Monitoring is a very helpful way to make sure that which node becomes primary in case if one of the interface fails in Reth interface.

Requirement – Make sure if Ge-0/0/4 fails on SRX1 RETH0, traffic should not be impacted and SRX2 should take over automatically. Also, when SRX1 RETH0 ge-0/0/4 comes up, SRX1(node0) should become primary again

Toplogy

topology

Pinging from server to reth0 172.20.101.1 from server and everything looks good

1_before_disabling_member_interface

I am disabling the interface ge-0/0/4 and also see the status of reth0 as soon as i do that.

2_disabling the interface_on pri

Ping has not stopped, despite of us having an other interface ge-5/0/4

3_ping_stopped_from_server_to_reth

Now configuring interface Monitoring

4_configuring_interface_monitoring

Verify now if the Reth0 has comeup

4.5_show_output

As soon as we did that, ping resumed

5_ping_resumed

Finally, after enabling the interface again, node0 has become primary for this RG  group, pre-empt has been enabled.

6_use_of_pre-empt

Regards

Rakesh M