pfSense is an open sourcefirewall/router computer software distribution based on FreeBSD. It is installed on a physical computer or a virtual machine to make a dedicated firewall/router for a network. It can be configured and upgraded through a web-based interface, and requires no knowledge of the underlying FreeBSD system to manage
pFsense Hardware Requirements and Guidelines *Same as for FreeBSD*
Physical Hardware Appliances for pFsense, Mikrotik RouterOS and many others….
Great Appliances for pFsense *and Mikrotik RouterOS amongst many others* to consider before purchasing Netgate appliances (pFsense supported HW Appliance Provider)
I saw many promising ones on Aliexpress both in 1U form factor and in small NUC size appliance also * i found this seller reputable and with great customer reviews however myself have not had the chance nor funds to buy one yet but the 1U one linked here is indeed on my perview*
A firewall is a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules.
Firewalls have been a first line of defense in network security for over 25 years. They establish a barrier between secured and controlled internal networks that can be trusted and untrusted outside networks, such as the Internet.
A firewall can be hardware, software, or both.
Terms regarding Traffic flow and link to an article of Data Center Architecture/Designs:
Egress / Ingress Concept
Ingress traffic is composed of all the data communications and network traffic originating from external networks and destined for a node in the host network.
Ingress traffic can be any form of traffic whose source lies in an external network and whose destination resides inside the host network. Ingress traffic can be from all applications accessed via a remote server or over the Internet.
Egress traffic is the reverse of ingress traffic. Egress is all traffic is directed towards an external network and originated from inside the host network.
Think for a moment that you are a router, your left hand is the WAN and your right hand is the LAN. Whenever you say Ingress, it means traffic is towards you, depending on the hand you are looking at. When you upload data to the internet its going out of your local network so the traffic is egress based on the LAN’s perspective but not the router, it will treat that data as ingress since is coming towards it. The only time it will be egress is if it finished sending it to its WAN interface out to the internet. So if you are looking at the routers Netflow data, the ingress and the egress will always be the same value; In order for you to get the true value of your ingress and egress data, you have to look into the interface Netflow data.
North – South , East-West Concept
North/South – Meaning traffic coming into and out of the network into Internet space, i.e in and out of edge firewalls and/routers.
East/West – Traffic internal to the network that doesn’t leave, i.e. LAN client to server and server to server communications.
Another explanation from Microsoft as a DC DataCenter point of view
East-West – East-West refers to traffic flows that occur between devices within a datacenter. During convergence for example, routers exchange table information to ensure they have the same information about the internetwork in which they operate. Another example are switches, which can exchange spanning-tree information to prevent network loops.
North | South – North- South refers to traffic flows into and out of the datacenter. Traffic entering the datacenter through perimeter network devices is said to be southbound. Traffic exiting via the perimeter network devices is said to be northbound.
Types of firewalls
An early type of firewall device, a proxy firewall serves as the gateway from one network to another for a specific application. Proxy servers can provide additional functionality such as content caching and security by preventing direct connections from outside the network. However, this also may impact throughput capabilities and the applications they can support.
Stateful inspection firewall
Now thought of as a “traditional” firewall, a stateful inspection firewall allows or blocks traffic based on state, port, and protocol. It monitors all activity from the opening of a connection until it is closed. Filtering decisions are made based on both administrator-defined rules as well as context, which refers to using information from previous connections and packets belonging to the same connection.
Unified threat management (UTM) firewall
A UTM device typically combines, in a loosely coupled way, the functions of a stateful inspection firewall with intrusion prevention and antivirus. It may also include additional services and often cloud management. UTMs focus on simplicity and ease of use.
Firewalls have evolved beyond simple packet filtering and stateful inspection. Most companies are deploying next-generation firewalls to block modern threats such as advanced malware and application-layer attacks.
According to Gartner, Inc.’s definition, a next-generation firewall must include:
Standard firewall capabilities like stateful inspection
Integrated intrusion prevention
Application awareness and control to see and block risky apps
Upgrade paths to include future information feeds
Techniques to address evolving security threats
While these capabilities are increasingly becoming the standard for most companies, NGFWs can do more.