Text 4 to answer questions 21 and 22.
1 -------Enterprise-class firewalls, such as those made by
----FORTINET, Cisco Systems and NetScreen Technologies,
----have long been marketplace commodities. Out of the box,
4 --they provide reliable, relatively easy-to-use security
----solutions. Buying some licenses from vendors can also
----provide 24/7 support and ongoing maintenance. In
7 --addition, commercial firewalls have configuration
----facilities, usually through graphical interfaces, and
----facilitated interaction with other security technologies such
10 --as SIEM, EDR, DRP, etc.
---------But commercial firewalls have a problem: many
----would say that they are expensive. That is why some IT
13 --teams consider the use of other options like open-source
----firewalls. iptables®, for example, is a freeware Linux tool
----developed by NetFilter that isn’t nearly as easy to use, but
16 --it’s quickly catching up in features and functionality.
---------iptables® firewall boasts many features normally
----found only in commercial firewalls, including packet
19 --defragmentation, rate limiting, integration of VPNs, scale
----up and scale down, packet content inspection and protocol
----state tracking.
22 -------So why don't we always use iptables® firewall instead
----of proprietary applications or devices? In addition to the
----support from manufacturers that the more traditional choice
25 --has, we can highlight iptables’® need for professional
----training, and also the need for hiring large support teams,
27--which could cost even more money in some scenarios.
Disponível em:<https://searchsecurity.techtarget.com/opinion/Commercialfirewalls-vs-Open-source-firewalls>. Acesso em 20 mar. 2021, com adaptações.
