Routing is the basic functionality of a device that controls the flow of traffic back and forth from one network to another. Learn the difference between a traditional firewall, a router, a gateway, and how the three interoperate.
- [Narrator] For the longest time I didn't really understand the difference between a Router and a Gateway, but is actually really helpful to know that difference. A Gateway is a software mechanism through which a Router can reach another network. Typically the upstream network is the internet, but it doesn't have to be, so the Router is the device which usually sits at a meeting point between two or more networks and a Gateway is like a digital portal to a different network through which the the Router may send data. If multiple upstream networks or wide area networks or LANS are in use or if there are multiple accounts to the internet through different gateways the associated gateways must be defined in your router for the traffic to route properly. So how does this relate to firewalls? A firewall frequently is loaded onto the same hardware that performs the routing on the network and so you'll sometimes hear of firewall routers in much the same way that you will sometimes hear gateway routers paired for simplicity sake in conversation or by product manufacturers. What makes a firewall useful is that it controls access to the gateways and the networks beyond those gateways which rules what you set. You can created static rules and floating rules rules can allow network traffic or deny it in one direction through a gateway or in both directions. A traditional firewall pays attention to where traffic is going and where it came from, but not really what the traffic is. Traditionally a firewall acts upon a transmission as it arrives at the gateway, The transmission or traffic called an IP packet shows up and tells the gateway which port it is destined for, Port 25 for unencrypted mail for example, Port 443 for an encrypted web-page. The firewall checks where the packet wants to go against it's set of rules and either allows the packet to route where it wants to go or denies the request and either unceremoniously drops the packet or sends a rejection notice back to its point of origin. Advanced firewalls can be configured to not only allow or disallow traffic bounds for different ports in the network, but can also dig into traffic itself down to the packet level and can analyze and act on those packets based on their contents regardless of which port there headed to or from. Advanced firewalls can be configured to even shape traffic by prioritizing certain network traffic types over or under other types of traffic or even traffic associated with certain applications regardless of the ports being used. Beyond what advanced firewalls can do we can now use Artificial intelligence applications like SNORT and others to monitor the network for intrusion looking for know exploits and preventing their use Watching user activity and protecting them without admin interaction and much much more.
- Designing your network
- Creating firewall schedules and rules
- Setting up a virtual IP
- Using aliases to group hosts
- Preventing local traffic from exiting to the internet
- Using Snort and other intrusion detection systems
- Prioritizing VoIP traffic
- Blocking access to specific websites
- Troubleshooting gaming performance issues
- Interpreting TCP flag definitions