Core Issue
Users cannot add the existing gateways to the route group because these gateways already belong to the route patterns.
Users can associate a gateway with a route group or a route pattern, but not both. This is a design decision to encourage the Route Pattern > Route List > Route Group > Gateway hierarchy.
In other words, users cannot have a gateway as part of a route group and then point a route pattern to that specific gateway.
Resolution
To add exisiting gateways to the route group, perform this procedure:
- Remove the associated gateways from the route pattern.
- Re-associate the same gateways with any number of route groups.
A route group may have multiple gateways, as long as they are not already associated with route patterns. A route list may have multiple route groups associated with it. A route pattern may have only one route list to block or route.
Also, when the gateways belong to the route pattern, any changes made on the route pattern end up resetting the route list and not the gateway. It is always recommended to first create the route group and the route list, and configure gateways in the route group. Associate route group to route list and route list to route pattern.
This ensures that when changes are made on the route pattern, only the route list gets reset and not the gateway.
For information on configuring route groups and route lists, refer to these documents: