Although a firewall offers protection for your network, it also costs money and creates an impediment to traffic flow, so you should look for one that is as cost effective and efficient as possible.
Later on this module, the firewalls are grouped into classes to differentiate them, but before selecting a firewall, you need to determine what your requirements are, taking the following considerations into account: What is the available budget?Every firewall in the environment should provide the highest possible level of service while remaining cost-effective, but be aware of the resultant damage to your business if the firewall is too restricted by cost.Many types of firewalls are available, differentiated partly by price, but also on features and performance.Generally, the more expensive the firewall, the more power and features it has.The module will also provide you with information on some of the most damaging intrusions so that you can determine which are most likely to occur in your environment and how intrusions can be prevented, not just by installing a firewall but, for example, by tightening up server configurations or discussing controls with your Internet Service Provider (ISP).
This module also defines different classes of firewalls and using the design guidelines you should be able to select the most appropriate class of firewall to meet your requirements.But on same computer with new doamin user who try to log on to the domain wirelessly will fail. (I had to connect the computer to wired connectio again and log on the new user to solve the problem) 1. Connected clients need to find DC which is probably inside your network and they need domain dns for that. Looks like users are using cached credentials when logging to computer (so they need to be logged in once before), meaning that wifi connection is not established until user logs in.I will check the document again (haven't done it in a long time) and try to guess what the problem is.In my client pc, it successfully received certificate though wired connection.However when I switched to wireless, it stuck in validating identity status forever. I just made it work after I placed my AP inside my network.There may already be firewalls in the environment that can be reused and routers that can have a firewall feature set installed.