We currently have a network of 192.168.0.0/23 which gives us 192.168.0.1-192.168.1.254. We have another remote location through site to site vpn that uses 192.168.3.0/24 and a 3rd site to site that uses 192.168.4.0/24. We are running out of IPs and trying to decide what is best. We are considering setting up a vlan for each department and giving them their own block of IPs. We are considering supernetting the 192.168 network for all departments. Each department would have 512 addresses. 192.168.0.0/23 for one, 192.168.2.0/23 for another, 192.168.4.0/23, 192.168.6.0/23 etc. Are there any potential problems with doing this? Is it better to subnet a class a or b using 10.0.0.0 or 172.16.0.0 or will it not matter. It will be substantially easier to stay with 192.168.0.0/23 due to the fact that much less will need changed in order to do that.
I am trying to come up with a plan that is best for the next 30 years and that will be easiest to implement. Any ideas?