A firewall is a cybersecurity tool that monitors and filters incoming and outgoing network traffic in accordance with the security policies that have already been established by an organization. At its most basic level, a firewall is essentially the barrier that stands between a private internal network and the public Internet. The main function of a firewall is to let safe traffic in while blocking dangerous traffic.
Types of Firewalls:
1. Filtering of packets:
A small amount of data is examined and dispersed in accordance with the standards of the filter.
2. Proxies service:
a network security system that guards application-layer message filtering.
3. Deliberate inspection:
Active connections are monitored by dynamic packet filtering to decide which network packets to let through the firewall.
4. Next Generation Firewall (NGFW):
Deep packet inspection on Next Generation Firewalls (NGFW) Application-level firewall monitoring.
10 tips for improving cybersecurity inside the firewall
1. Keep in mind that internal security and perimeter security are two distinct things
A different threat model exists for internal security than for perimeter security. With the help of zero-day vulnerabilities in widely used Internet services like HTTP and SMTP, perimeter security protects your networks from Internet intruders. While sophisticated hackers can gain access to your network using scripts, a janitor can access it just as easily by plugging into an Ethernet jack.
2. Restricted VPN access
Because virtual private network clients place unhardened desktop operating systems outside the corporate firewall’s perimeter protection, they pose a serious internal security risk. Be clear about the resources that VPN users may access. Don’t give access to the entire internal network to every VPN user. Apply access-control lists to restrict classes of VPN users’ access to only the intranet resources or mail servers they require.
3. Create perimeters for partner extranets akin to the Internet
Partner networks play a part in the issue with internal security. The Slammer worm brought down networks because businesses had allowed their partners access to internal resources, despite the fact that savvy security administrators know how to configure their firewalls to block MS-SQL. Create a DMZ for each partner, place the resources they require there, and forbid any other users from accessing your network since you have no control over the security policies and procedures of your partners.
4. Track cybersecurity policy automatically
Effective security practices depend on intelligent security policies. The problem is that the ability to manually modify security policy is significantly outpaced by changes in business operations. Because of this reality, you must develop automated techniques for identifying modifications to business procedures that call for security policy reconciliation. This can range from being as detailed as keeping track of when employees are hired and let go to being as basic as monitoring network traffic and noting which computers communicate with which file servers. Above all, make sure that whatever procedure you create to uphold your security policy is simple enough to continue being used on a daily basis.
5. Disable any unnecessary network services
A typical corporate network may have 95 additional servers listening on the SMTP port in addition to the four or five servers that are actively involved in email delivery on a large corporate network. The 95 hosts that are most likely to contain latent mail server vulnerabilities are as follows. Look for services that shouldn’t be running on the network. Disable file-sharing protocols on any computers running Windows that have never served as file servers.
6. Protect important resources first
It is unrealistic to assume that every host can be kept secure and patched on a network with 30,000 devices. The challenge of triaging security exists in a typical large network. A cost-benefit analysis should be done. Finding, cataloging, patching, and hardening each Web server on the network could take a month. That shouldn’t stop you from locating important Web servers and locking them down first, such as the one that keeps track of all your sales leads. The most important resources for your company can be determined fairly quickly. Find them on the network, then secure them.
7. Create a safe wireless network
Check for wireless on your network. Take out malicious wireless access points. Recognize that wireless network access, which provides secure wireless access, is a genuinely alluring and useful facility. Place an access point outside the boundaries of your perimeter firewalls and enable VPN access for users. If your network already offers wireless access, it is much less likely that users will go out of their way to create rogue wireless access points.
8. Create protected visitor access
The internal network shouldn’t be made accessible to guests. A “no Internet access from the conference room” policy is often attempted to be enforced by security engineers. Due to the difficulty of tracking visitors from other desks, this may force employees to grant unauthorized access to them. Create visitor network segments outside the perimeter firewalls for conference rooms.
9. Establish virtual boundaries
As long as hosts are controlled by humans, they will continue to be susceptible to attack. Make the objective that no host grants an attacker full access to the network if it is compromised rather than setting unrealistic goals like “, no host should be Create virtual boundaries around your business units once you have an understanding of how your network is being used. If a marketing user’s account has access to corporate R&D, the attacker shouldn’t have it. The computer is compromised. Implement access controls between marketing and R&D. We are capable of creating boundaries between the internal network and the Internet. It’s time to consider how to create boundaries on the network between the various business user groups.
10. Explain security choices
In efforts to increase network cybersecurity, users of the network are a crucial partner. Normal users might not understand the distinction between RADIUS and TACACS, or between a proxy and a firewall with packet filtering, but if you are honest and upfront with them, they will likely cooperate. Make it simple for regular users to use the network. Users will be more receptive to security requirements if they never have unpleasant encounters with burdensome security procedures.