Resource Library
Time：2020-06-11Source：UTEPO
Switches and firewalls are all essential pieces of equipment needed to run and protect your network. While these components are often confused due to their similar appearance (metal boxes with physical ports and LED status lights) each one serves a specific function. Here is a closer look at the distinguishing features and capabilities of each network device.
WHAT IS A SWITCH
A switch is an intelligent, high-performance hub. As data is sent back and forth through the switch, it records MAC addresses (unique identification number for network-enabled hardware) for each sender and recipient. In this process, the switch learns which device is connected to which port.
In a local area network (LAN), a switch is similar to a bridge in a city. Its main function is to connect other network devices (routers, firewalls, and wireless access points) and connect client devices (computers, servers, network cameras, and IP printers). In short, a switch can provide a central connection point for all the different devices on the network.
WHAT IS A FIREWALL
A firewall, also known as a shield, is a network security system that is set between an internal network and an external network. Typically, firewalls can protect internal/private LANs from external attacks and prevent important data from being compromised. In the absence of a firewall, the router passes traffic blindly between the internal network and the external network with no filtering mechanism, and the firewall not only monitors the traffic but also blocks unauthorized traffic.
In short, his work is anti-virus, intrusion prevention, URL filtering, file filtering, content filtering, application behavior control, mail filtering, protection against common DDoS attacks, traditional single packet attacks. You may still have following question.
1. Does the switch have the firewall function? Can I use it as a firewall?
Normal switches do not have this function, because firewall functionality is carried out over layer three, so it is possible to support firewall functionality only with layer 3 switches.
For example, some Layer 3 switches can be configured with ACL (access control rules, filtering packets on the interface according to set conditions) rules, behavior control, and other partial firewall functions. In cases where network security requirements are not high, it is possible to completely ignore firewalls.
2. Does the firewall have a routing function? Can it be used as a route?
This is a controversial issue. Now, the firewall has router function, so you can replace the router directly with the firewall in many times. And you can take the firewall as the exit in your new networks directly.
We can understand the similarities between the firewall and the router from the three modes.
There are three deployment modes for firewall, routing mode (also called gateway mode), transparent mode, bypass mode.
ROUTING MODE
It is widely used to deploy and configure NAT, routing, and port mapping. All firewall functions are available in this mode.
When the firewall is located between the internal network and the external network, you need to configure the interfaces between the firewall and the internal network, the external network, and the DMZ as the IP addresses in different network segments and re-plan the original network topology, which is equivalent to a router.
TRANSPARENT MODEL
It is mostly used in serial and network to protect the borders of two inaccessible security domains. The port mapping function, NAT function, and VPN function are not available in this mode.
BYPASS MODE
In Bypass mode, the firewall allows all traffic to pass through without any scanning. In this mode, one or two pairs of interfaces are bridged allowing uninterrupted traffic flow.
