Packet-Filtering Firewalls
When it comes to types of firewalls based on their method of operation, the most basic type is the packet-filtering firewall. It serves as an inline security checkpoint attached to a router or switch. As the name suggests, it monitors network traffic by filtering incoming packets according to the information they carry.
Packet-Filtering Firewalls
When it comes to types of firewalls based on their method of operation, the most basic type is the packet-filtering firewall. It serves as an inline security checkpoint attached to a router or switch. As the name suggests, it monitors network traffic by filtering incoming packets according to the information they carry.
As explained above, each data packet consists of a header and the data it transmits. This type of firewall decides whether a packet is allowed or denied access based on the header information. To do so, it inspects the protocol, source IP address, destination IP, source port, and destination port. Depending on how the numbers match the access control list (rules defining wanted/unwanted traffic), the packets are passed on or dropped.
If a data packet doesn’t match all the required rules, it won’t be allowed to reach the system.
A packet-filtering firewall is a fast solution that doesn’t require a lot of resources. However, it isn’t the safest. Although it inspects the header information, it doesn’t check the data (payload) itself. Because malware can also be found in this section of the data packet, the packet-filtering firewall is not the best option for strong system security.
| PACKET-FILTERING FIREWALLS | |||
| Advantages | Disadvantages | Protection Level | Who is it for: |
| – Fast and efficient for filtering headers.– Don’t use up a lot of resources.
– Low cost. |
– No payload check.– Vulnerable to IP spoofing.
– Cannot filter application layer protocols. – No user authentication. |
– Not very secure as they don’t check the packet payload. | – A cost-efficient solution to protect devices within an internal network.– A means of isolating traffic internally between different departments. |
