Description

This article explains that rebooting an SRX device that is already working in flow packet-mode (or any other forwarding mode) will not change the forwarding mode.

Symptoms

For this example, a device is already set in "Inet forwarding mode: packet based," and a reboot command is issued. 
Post-reboot, the same operating flow mode is present; it will not change.
This is also available for power-off followed by a power-on. 

Solution

Related document on how to switch between flow and packet mode:
 
>>>Example of how to change the forwarding mode based on KB30461 [juniper.net].
 
​***Device is currently running in Inet forwarding mode: flow based
labroot@jtac-srx345> show security flow status  
  Flow forwarding mode:
    Inet forwarding mode: flow based
    Inet6 forwarding mode: drop
    MPLS forwarding mode: drop
    ISO forwarding mode: drop
    Tap mode: disabled (default)
    Enhanced route scaling mode: Disabled
  Flow scaled L3L4 mode:
    Scaled L3L4 mode: Disabled
  Flow trace status
    Flow tracing status: off
  Flow session distribution
    Distribution mode: RR-based
    GTP-U distribution: Disabled
    SCTP distribution: Enabled
  Flow gre performance acceleration: off
  Flow packet ordering
    Ordering mode: Hardware
  Flow power mode: Disabled
  Flow power mode IPsec: Disabled
  Flow power mode IPsec QAT: Disabled
  Fat core group status: off
  Flow inline fpga crypto: Disabled
  Flow multicast strict-order: Disabled
  Flow Drop-flow Summary:
    Maximum Drop-flow sessions: 38400
    Timeout: 4s
    Logging: Disabled
 
​***Changing  Inet forwarding mode to packet-based 
labroot@jtac-srx345# set security forwarding-options family inet mode packet-based 
 
[edit]
labroot@jtac-srx345# show | compare 
[edit]
+  security {
+      forwarding-options {
+          family {
+              inet {
+                  mode packet-based;
+              }
+          }
+      }
+  }
 
[edit]
labroot@jtac-srx345# commit and-quit 
warning: You have changed inet flow mode "MODE-FLOW"->"MODE-PACKET".
warning: You must reboot the system for your change to take effect.
If you have deployed a cluster, be sure to reboot all nodes.
commit complete
Exiting configuration mode
 
 
***The show security flow status command states that it operates in packet-mode, but a reboot is needed, as stated after the commit:
Warning:
warning: You have changed inet flow mode "MODE-FLOW"->"MODE-PACKET".
warning: You must reboot the system for your change to take effect.
If you have deployed a cluster, be sure to reboot all nodes.
commit complete
 
***Reboot the device
labroot@jtac-srx345> request system reboot 
Reboot the system ? [yes,no] (no) yes
 
 
 
​***Post reboot: Inet forwarding mode changed from flow based to packet based
labroot@jtac-srx345> show security flow status  
  Flow forwarding mode:
    Inet forwarding mode: packet based
    Inet6 forwarding mode: drop
    MPLS forwarding mode: drop
    ISO forwarding mode: drop
    Tap mode: disabled (default)
    Enhanced route scaling mode: Disabled
  Flow scaled L3L4 mode:
    Scaled L3L4 mode: Disabled
  Flow trace status
    Flow tracing status: off
  Flow session distribution
    Distribution mode: RR-based
    GTP-U distribution: Disabled
    SCTP distribution: Enabled
  Flow gre performance acceleration: off
  Flow packet ordering
    Ordering mode: Hardware
  Flow power mode: Disabled
  Flow power mode IPsec: Disabled
  Flow power mode IPsec QAT: Disabled
  Fat core group status: off
  Flow inline fpga crypto: Disabled
  Flow multicast strict-order: Disabled
  Flow Drop-flow Summary:
    Maximum Drop-flow sessions: 38400
    Timeout: 4s
    Logging: Disabled
 
 
>>>A reboot will not change the current setting for forwarding mode:
***To test if the Inet forwarding mode remains packet based, reboot the device:
 
labroot@jtac-srx345> request system reboot 
Reboot the system ? [yes,no] (no) yes
 
​***Post reboot the Inet forwarding mode remains in packet based
 
labroot@jtac-srx345> show security flow status 
  Flow forwarding mode:
    Inet forwarding mode: packet based
    Inet6 forwarding mode: drop
    MPLS forwarding mode: drop
    ISO forwarding mode: drop
    Tap mode: disabled (default)
    Enhanced route scaling mode: Disabled
  Flow scaled L3L4 mode:
    Scaled L3L4 mode: Disabled
  Flow trace status
    Flow tracing status: off
  Flow session distribution
    Distribution mode: RR-based
    GTP-U distribution: Disabled
    SCTP distribution: Enabled
  Flow gre performance acceleration: off
  Flow packet ordering
    Ordering mode: Hardware
  Flow power mode: Disabled
  Flow power mode IPsec: Disabled
  Flow power mode IPsec QAT: Disabled
  Fat core group status: off
  Flow inline fpga crypto: Disabled
  Flow multicast strict-order: Disabled
  Flow Drop-flow Summary:
    Maximum Drop-flow sessions: 38400
    Timeout: 4s
    Logging: Disabled

Modification History

28-10-2026 Initial draft