Network Devices

This device is a data link layer device. It is available either as a standalone or integrated with other devices, such as wireless routers or modems that can plug in physical devices. It keeps the traffic between the source and destination ports from interfering with other devices in the network.

Switch

This device operates at the network layer and can connect your home network to the Internet. Or, in a business or institutional scenario, it can connect your webserver to your database server.

Router

This can operate at multiple layers of the OSI model, including data link, network, transport, session, and application - and in certain circumstances, presentation as well.

Firewall

At what layers does the firewall defines what traffic should go between two networks?

data link and network

At what layer are the firewall filter settings are port-based?

transport

The firewall that operates at the network and

transport layers is called what?

the Layer 4 firewall

The firewall that works at the session, presentation, and application layers is what?

the Layer 7 firewall.

What layer firewall is also smart enough to decrypt and analyze the content flowing through, thereby adding one more level of filtering to the IP address and port combination?

The Layer 7 firewall

What is thus a powerful tool that can help prevent malicious attacks like Structured Query Language, also known as SQL injection, or other malware?

A firewall