Most of our networks consist of 4 different pieces of equipment. When troubleshooting a network or speaking with IT, it is best to be aware of these components.
1. Modem:
Modems are pieces of equipment that is almost always supplied by the Internet Service Provider (ISP). What this equipment primarily does, is unpack data packets from outside our internal network, and rebuilds them to fit our internal networks specifications. Additionally, almost all modern modems are capable of routing data around the network so all data goes where it's meant to go. Our network however, has firewalls that do routing themselves; Because of this, all of our modems should be set up with Passthrough mode (most commonly referred to as "Bridge mode"). This is important to set up and can be done by calling the ISP and asking for them to make the change on the new modem, as they are not set up that way when provided by the ISP. It's also important to verify that the modem is a business modem and not a residential one. While residential modems may work a lot of the time, it will likely show issues once it faces full work load from various users.
2. Firewall:
Our firewalls keep uninvited guests out of our networks, provides security against malicious websites the security community believes to be dangerous, and blocks access to websites the company finds inappropriate or dangerous for work. This device should be the only one plugged into the modem. Exceptions to this are extremely rare and do not exist within our environment at this time.
Additionally, our firewalls use routing protocols to map out the network for proper distribution of network pathways and to make sure data is going where it's supposed to go by passing it through either the modem or out to users. They also possess multiple network ports, so users can plug into them or to switches, which provide additional network ports. The wifi access points can be plugged into this device or the switches.
3. Switch:
Network switches exist within a network to create additional hardline connections. These devices normally have between 5 and 30 ports and may occasionally be set up for redundancy. These devices sit between the firewall and networked equipment (printers, computers, access points). It is their job to pass data packets to the appropriate equipment and stop network packets from colliding.
In other words, if network packets are cars, the switch is the Department of Transportation. It tells what roads cars are allowed to travel on and provides traffic lights to allow for smoother traffic flow.
4. Access Point (AP):
These devices connect wireless devices to the network. Access Points are placed on ceilings and walls and should exist as close to users as possible. With multiple APs connected to a network, users can move around the office without losing a connection or facing an interruption. APs speak with each other so that wireless devices can move from one to the other without noticing on their side.
It is worth knowing that modern APs are supported with Power Over Ethernet (POE). What this means is that it does not get power from a power outlet, but through the network cable that connects it to the switch or firewall. If a restart is required, this can be done by restarting the equipment the AP is connected to.