Note: The Packet Capture Feature can also be used to capture 'self-traffic' (e.g. Dynamic Routing Protocol messages, ARP, management traffic, ICMP to Routing Engine). However, this Packet Capture feature is not available on the SRX High-End devices.
For SRX High-End devices, packet capture can be achieved using the datapath-debug feature. Refer to the following:
Packet Capture of control traffic to and from the RE of the SRX
Use the 'monitor traffic interface' command to capture 'self-traffic', i.e. packets destined to and from the RE (Routing Engine) of the Junos device. This feature is useful for troubleshooting why one can't telnet to the SRX device, or for troubleshooting if a SNMP request is being received and transmitted from the SRX device, or for troubleshooting OSPF, BGP, and PPP connectivity issues.