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Secure Network Architecture Desing

Few days back I was going through an article on "Managing Network Security". Although it was a bit technical, it presented some fundamental idea about designing secure network architecture of an organization. I just picked up few points from the article easy-to-grasp, left the detailed and technical ones.
Design a secure network architecture:

1. Make sure hosts are not permitted to access the Internet directly. They should access
it through content filtering proxies capable of scanning the packets for malicious code. If
they need to be connected by a NAT rule on the firewall, ensure that the necessary network
and security controls (such as desktop firewall, antivirus and antispyware tools) are
present on the host.

2. All emails should pass through a secure mail gateway that is capable of filtering email threats.

3. Implement strong authentication for accessing networked resources.

4. Host hardening lowers the chances of system compromise or exploitation. Stick to best
practices of system installation, followed by hardening and conducting of regular vulnerability
scans. Hardening hosts and network devices directly after installation considerably reduces the attack surface.

5. If your organization uses wireless as a network connectivity option, ensure that proper
security controls are placed to safeguard the flowing of data through a wireless network.
Some of the security measures to be taken are:
a) Secure the wireless access via VPN tunnels or strong encryptions like WPA2.
b) Wireless access points should be hardened and endpoint security measures should be taken.
c) Implement wireless IPS and rogue device detection techniques.

6. Implement a strong password policy in your organization to safeguard online accounts
against password attacks such as brute force, dictionary or hybrid password attacks.

7. Use automated tools to gather network information on a regular basis and analyze them. Create the latest network map based on the information and a list of assets belonging
to your organization. This assists in the detection of rogue devices on wired or wireless
networks. Maintain and update the switch port, router port configuration document. Keep
unused ports disabled on all network points.

8. Use a Security Information and Event Management tool to obtain meaningful security
logs and events correlations. SIEM/SIM tools assist in infrastructure security by providing
important logs to centralized security server and correlate them at that point. It helps IT
security operations personnel be more effective in responding to external and internal
threats.

These points figure out an ideal architecture of an oragnization or how it should be.

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