This article describes the issue of second control link failure on 3400/3600 SRX chassis cluster.
Dual Control Links are configured on 3000 SRX Series Chassis Cluster, with one CRM installed on each member. The second control link does not work.
Symptoms:
Not able to activate the redundant control link. We can see both the devices are sending signals on the second control link, but not receiving any on either end.
{primary:node0}
root@SRX3400-1> show chassis cluster control-plane statistics
Control link statistics:
Control link 0:
Heartbeat packets sent: 453055
Heartbeat packets received: 453053
Heartbeat packet errors: 0
Control link 1:
Heartbeat packets sent: 453055
Heartbeat packets received: 0
Heartbeat packet errors: 0
Fabric link statistics:
Probes sent: 453053
Probes received: 452789
Probe errors: 0
{secondary:node1}
root@SRX3400-2> show chassis cluster control-plane statistics
Control link statistics:
Control link 0:
Heartbeat packets sent: 899571
Heartbeat packets received: 899379
Heartbeat packet errors: 0
Control link 1:
Heartbeat packets sent: 899571
Heartbeat packets received: 0
Heartbeat packet errors: 0
Fabric link statistics:
Probes sent: 899569
Probes received: 898851
Probe errors: 0
Second control LED stays green even when the fiber cable is removed. Second Control LED should have gone dark or stopped glowing, as shown in the images below:


2020-07-02: Article reviewed for accuracy; Minor changes added to highlight identifying problem state and link for certified SFP modules.