Configuring sync on GTM devices.

GTM sync groups do not have peer configured like other BIG-IP systems but instead you simply add a GTM to an existing group using 'gtm_add' script on the CLI.

To get GTM Sync Group working you need to ensure you have Datacenters and GTM devices defined as Servers with the correct IP addresses.

Also see for BIG-IP GTM synchronization group requirements:

I found a lack of initial setup information when I received new BIG-IP GTM devices, so here is the full list of steps I took to set up the GTM sync group after getting the device on the network. This was performed on version 12.1.3 devices.

• License/Provision devices
• Go to Platform to set Management IP, Hostname, Timezone, and admin/root passwords
• Go to Network Click Finished to perform device setup manually
• Create VLAN on both devices
• Create Self IP on both devices (set Port Lockdown to Allow Default)
• Create Default Route if necessary on both devices
• Go to System > Configuration > Device > NTP to configure NTP on both devices
• Renew Device Certificate using new Hostname on both devices
• Add DNS Listeners on both devices using Self IP
• Add Trusted Device Certificates on both devices
• Add Trusted Server Certificates on both devices (same certificate as in previous step)
• Create Data Centers on both devices
• Create Prober Pools on both devices (one for each Data Center)
• Create a Server for each device on both devices
• Assign each Server to its respective Prober Pool
• Go to DNS > Settings > GSLB > General
• Click checkboxes for Synchronize and Synchronize DNS Zone Files on both devices.* Ensure that the Group Name is the same between these devices, and different from any other GTMs that are in your environment.* Click Update!

And that should do it! As long as your Firewalls/ACLs are allowing Destination Port 4353 between the devices... This is just meant to be a very simple guide, so there may be other considerations to think about when performing these steps in your environment. Hope this helps somebody out there!