Both 2.8 and 2.9 documentations for networking are lacking in a couple of areas :

 - the subctl installation does not feature what is needed to mirror it so it can be used to diagnose managed cluster issues in a disconnected (air-gapped) cluster.

• we want to expand the globalnet configuration to add a globalnetCIDRange setup section that will need to mention that by default it is 242.0.0.0/8 and that a /8 is needed as by default submariner gives each managed cluster a /16.

The existing documentation is at :

• 2.8 
  • subctl at https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.8/html-single/networking/index#installing-subctl-command-utility
  • globalnet at https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.8/html-single/networking/index#deploying-submariner-console and  https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.8/html-single/networking/index#submariner-globalnet
• 2.9
  • subctl section at https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.9/html-single/networking/index#installing-subctl-command-utility
  • submariner globalnet section at https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.9/html-single/networking/index#deploying-submariner-console and https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.9/html-single/networking/index#deploying-submariner-mcaddon-api

The changes required are :

• for subctl, add information on what to mirror for usage on managed cluster. specifying which version of subctl to use for the version of submariner used is also useful here.
• for globalnet we need to incorporate more details on the configuration of CIDR, the official page is more detailed and we should also be (see architecture at https://submariner.io/getting-started/architecture/globalnet/)

this adds and updates topics to the existing documentation.