Related Documentation
- J Series
- Example: Configuring Chassis Cluster Control Ports
- Understanding Chassis Cluster Control Link Heartbeats
- Understanding Chassis Cluster Control Link Failure and Recovery
- Understanding the Chassis Cluster Control Plane
- SRX Series
- Example: Configuring Chassis Cluster Control Ports
- Understanding Chassis Cluster Dual Control Links
- Connecting Dual Control Links for SRX Series Devices in a Chassis Cluster
- Understanding Chassis Cluster Control Link Heartbeats
- Understanding Chassis Cluster Control Link Failure and Recovery
- Understanding the Chassis Cluster Control Plane
- Additional Information
- Junos OS Feature Support Reference for SRX Series and J Series Devices

Understanding Chassis Cluster Control Links
The control link relies on a proprietary protocol to transmit session state, configuration, and liveliness signals across the nodes.
On SRX5600 and SRX5800 devices, by default, all control ports are disabled. Each SPC in a device has two control ports, and each device can have multiple SPCs plugged into it. To set up the control link in a chassis cluster with SRX5600 or SRX5800 devices, you connect and configure the control ports that you will use on each device (fpcn and fpcn) and then initialize the device in cluster mode.
For SRX3400 and SRX3600 devices, there are dedicated chassis cluster (HA) control ports on the switch fabric board. No control link configuration is needed for SRX3400 and SRX3600 devices.
For SRX1400 devices, dedicated control ports on the SYSIO (port 10 and port 11) are available. When the devices are not in cluster mode, these ports can be used as revenue ports. No control link configuration is needed for SRX1400 devices.
For SRX240, SRX550, and SRX650 devices, the control link uses the ge-0/0/1 interface.
For SRX220 devices, the control link uses the ge-0/0/7 interface.
For SRX100 and SRX210 devices, the control link uses the fe-0/0/7 interface.
In a J Series chassis cluster, the control link is a physical connection between the ge-0/0/3 ports on each device, with both transformed into fxp1.
For details about port and interface usage for management, control, and fabric links, see SRX Series Chassis Cluster Slot Numbering and Port/Interface Naming and J Series Chassis Cluster Slot Numbering and Port/Interface Naming.
To set up the control link on J Series devices, you connect the control interfaces on the two devices back-to-back. When you initialize a device in cluster mode, Junos OS renames the control interface to fxp1 and uses that interface for the cluster control link. To enable the control link to transmit data, the system provides each fxp1 control link interface with an internal IP address.
Related Documentation
- J Series
- Example: Configuring Chassis Cluster Control Ports
- Understanding Chassis Cluster Control Link Heartbeats
- Understanding Chassis Cluster Control Link Failure and Recovery
- Understanding the Chassis Cluster Control Plane
- SRX Series
- Example: Configuring Chassis Cluster Control Ports
- Understanding Chassis Cluster Dual Control Links
- Connecting Dual Control Links for SRX Series Devices in a Chassis Cluster
- Understanding Chassis Cluster Control Link Heartbeats
- Understanding Chassis Cluster Control Link Failure and Recovery
- Understanding the Chassis Cluster Control Plane
- Additional Information
- Junos OS Feature Support Reference for SRX Series and J Series Devices


