Question: Is needed to make an update from 3.4.2.91 to 4.1.1.03 a new class b ip range for the CIDR or the CIDR with this update can use different ip ranges?
Release : 4.x
Yes, 4.1.1 has a solution for setting the docker network and you can change the network to a smaller network than a /16 class b network but this still needs to be a "private network" that can be internally routable and not simply a random address. In my example below I set the Gateway address (192.168.99.1) for a /24 network. You can use a /27 network in the same fashion but the gateway address must be appropriately set for that network so I normally suggest a simple /24 as it is easy to note the XXX.XXX.XXX.1/24 format without making mistakes. Incorrectly setting this network address may cause additional networking issues.