This article discusses the 'Standby is not synced' error, which can be seen on a device with configured GRES, NSR and subscriber-management features after a backup RE (routing engine) replacement.
After a backup RE replacement, it is recommended to check whether the routing engines are synchronized and ready for switchover. The following commands can be used. ( KB32931 - [Junos] List of commands to check for GRES readiness [juniper.net] ):
request chassis routing-engine master switch check (on the master RE)
show system switchover (on the backup RE)
The following error may be reported when "request chassis routing-engine master switch check" command is issued:
"request chassis routing-engine master switch check"
user@device-re0> request chassis routing-engine master switch check error: Standby is not synced
No issues are reported by the backup RE:
user@device-re1> show system switchover Graceful switchover: On Configuration database: Ready Kernel database: Ready Switchover Status: Ready
A configuration change can be successfully committed and synchronized:
user@device-re0# set interfaces lo0 description test [edit] user@device-re0# commit synchronize re0: configuration check succeeds re1: commit complete re0: commit complete
But the problematic output remains:
Before the replacement, if the newly inserted RE has the same JUNOS release as the primary RE, it is possible the newly inserted RE was not restarted after insertion and initial synchronization with the primary RE.
The following commands are required to enable subscriber-management features. RE restart is needed to apply such configuration change properly:
user@device> show configuration system services { subscriber-management { enable; } } user@device> show configuration chassis network-services network-services enhanced-ip;
Depending on the amount of DRAM of the RE, the following configuration may also be needed:
user@device> show configuration system configuration-database max-db-size 314572800;
Each of these commands requires RE restart to be applied properly. In order to apply this configuration, the backup RE must be restarted after it is synchronized with the primary RE. The following commands can be used on both primary and backup REs to verify the necessary commands to enable subscriber-management were applied properly, and the output should be similar on both REs.
show system subscriber-management statistics
show system configuration database usage
Outputs collected from the device running JUNOS 18.2R3-S2.9 in problematic condition (the backup RE was inserted, but wasn't restarted one more time):
Primary RE:
user@device-re0> show system configuration database usage Maximum size of the database: 300.00 MB Current database size on disk: 1.50 MB Actual database usage: 1.47 MB Available database space: 298.53 MB user@device-re0> show system subscriber-management statistics Session Manager started @ Tue Jun 1 20:37:34 2021 Session Manager cleared @ Tue Jun 1 20:37:34 2021 -------------------------------------------------------------- Packet Statistics -------------------------------------------------------------- I/O Statistics: -------------------------------------------------------------- Rx Statistics packets : 1115 Tx Statistics packets : 0 Layer 3 Statistics Rx Statistics packets : 0 Tx Statistics packets : 0
Backup RE:
user@device-re1> show system configuration database usage Maximum size of the database: 665.99 MB Current database size on disk: 1.50 MB Actual database usage: 1.47 MB Available database space: 664.52 MB user@device-re1> show system subscriber-management statistics subscriber-management not enabled command not supported
To notify the user of this issue, the following syslog message is generated by the backup RE when a configuration change (for example, change of an interface description) is committed:
Jun 1 21:10:08.868 device-re1 bbesmgd[6997]: %DAEMON-3: bbe-smgd: bbemg_read_tomcat_disabled_cfg:279 Reboot required - configuration change for subscriber-management