Network Security

 Network security consists of the provisions made in an underlying computer network infrastructure, policies adopted by the network administrator to protect the network and the network-accessible resources from unauthorized access and consistent and continuous monitoring and measurement of its effectiveness (or lack) combined together.

Comparison with computer security

Securing network infrastructure is like securing possible entry points of attacks on a country by deploying appropriate defense. Computer security is more like providing means to protect a single PC against outside intrusion. The former is better and practical to protect the civilians from getting exposed to the attacks. The preventive measures attempt to secure the access to individual computers--the network itself--thereby protecting the computers and other shared resources such as printers, network-attached storage connected by the network. Attacks could be stopped at their entry points before they spread. As opposed to this, in computer security the measures taken are focused on securing individual computer hosts. A computer host whose security is compromised is likely to infect other hosts connected to a potentially unsecured network. A computer host's security is vulnerable to users with higher access privileges to those hosts.


Attributes of a secure network

Network security starts from authenticating any user, most likely a username and a password. Once authenticated, a stateful firewall enforces access policies such as what services are allowed to be accessed by the network users. Though effective to prevent unauthorized access, this component fails to check potentially harmful contents such as computer worms being transmitted over the network. An intrusion prevention system (IPS) helps detect and prevent such malware. IPS also monitors for suspicious network traffic for contents, volume and anomalies to protect the network from attacks such as denial of service. Communication between two hosts using the network could be encrypted to maintain privacy. Individual events occurring on the network could be tracked for audit purposes and for a later high level analysis.

Honeypots, essentially decoy network-accessible resources, could be deployed in a network as surveillance and early-warning tools. Techniques used by the attackers that attempt to compromise these decoy resources are studied during and after an attack to keep an eye on new exploitation techniques. Such analysis could be used to further tighten security of the actual network being protected by the honeypot.




Security management

Security Management for networks is different for all kinds of situations. A small home or an office would only require basic security while large businesses will require high maintenance and advanced software and hardware to prevent malicious attacks from hacking and spamming.


Small homes
A basic firewall.
For Windows users, basic Antivirus software like McAfee, Norton AntiVirus or AVG Antivirus. An anti-spyware program such as Windows Defender or Spybot would also be a good idea. There are many other types of antivirus or antispyware programs out there to be considered.
When using a wireless connection, use a robust password. Also try and use the strongest security supported by your wireless devices, such as WPA or WPA2.

Medium businesses
A fairly strong firewall
Strong Antivirus software and Internet Security Software.
For authentication, use strong passwords and change it on a bi-weekly/monthly basis.
When using a wireless connection, use a robust password.
Raise awareness about physical security to employees.
Use an optional network analyzer or network monitor.

Large businesses
A strong firewall and proxy to keep unwanted people out.
A strong Antivirus software package and Internet Security Software package.
For authentication, use strong passwords and change it on a weekly/bi-weekly basis.
When using a wireless connection, use a robust password.
Exercise physical security precautions to employees.
Prepare a network analyzer or network monitor and use it when needed.
Implement physical security management like closed circuit television for entry areas and restricted zones.
Security fencing to mark the company's perimeter.
Fire extinguishers for fire-sensitive areas like server rooms and security rooms.
Security guards can help to maximize security.


School

An adjustable firewall and proxy to allow authorized users access from the outside and inside.
Strong Antivirus software and Internet Security Software packages.
Wireless connections that lead to firewalls.
Children's Internet Protection Act compliance.
Supervision of network to guarantee updates and changes based on popular site usage.
Constant supervision by teachers, librarians, and administrators to guarantee protection against attacks by both internet and sneakernet sources.


Large Government

A strong strong firewall and proxy to keep unwanted people out.
Strong Antivirus software and Internet Security Software suites.
Strong encryption, usually with a 256 bit key.
Whitelist authorized wireless connection, block all else.
All network hardware is in secure zones.
All host should be on a private network that is invisible from the outside.
Put all servers in a DMZ, or a firewall from the outside and from the inside.
Security fencing to mark perimeter and set wireless range to this.