Configuring subnets quandry

  1. You're totally right, 254 hosts are allowed, so you can add 234.
  2. Exactly, /28 would be too small, /27 fits fine (30 hosts allowed)
  3. Exactly.
  4. If you have a router, it can route traffic between the subnets (if they're connected of course and the router knows how to route between them).