F5 r2800 HA standby box shows offline even the the network reachability fine

Hi vadivelan,

Have you checked the self IP having port lockdown feature is default, many time in new versions it is set as none

The message "awaiting the initial config sync" typically indicates that units never were in synced state. 

(Maybe due to re-creating the sync-failover device group.) Please check both units for the device settings (failover, config sync, mirroring). 

Local self IPs need to be used for all these properties and the port lockdown should be set to "allow default". Both the devices network config do not sync to each other hance all the objects or config settings need to be done on both boxes individualy.

Both units are added to the new sync-failover device group? 

Device trust is established bi-directional (check device list on both machines). Make sure both units are on same time ("

ntpq -p

"). Watch the log file for error messages during config sync:

tail -f /var/log/ltm

run the below commands in BASH mode

grep -i cmi /var/log/ltm

grep -i configsync /var/log/ltm

I would refer the following article and try to troubleshoot.

https://support.f5.com/kb/en-us/solutions/public/13000/900/sol13946.html?sr=43152862

Hope this helps 

🙏