Conduct a Risk Analysis
A risk analysis should identify the risks to your network, network resources, and data. This doesn’t mean you should identify every possible entry point to the network, nor every possible means of attack. The intent of a risk analysis is to identify portions of your network, assign a threat rating to each portion, and apply an appropriate level of security. This helps maintain a workable balance between security and required network access.
Assign each network resource one of the following three risk levels:
- Low Risk Systems or data that if compromised (data viewed by unauthorized personnel, data corrupted, or data lost) would not disrupt the business or cause legal or financial ramifications. The targeted system or data can be easily restored and does not permit further access of other systems.
- Medium Risk Systems or data that if compromised (data viewed by unauthorized personnel, data corrupted, or data lost) would cause a moderate disruption in the business, minor legal or financial ramifications, or provide further access to other systems. The targeted system or data requires a moderate effort to restore or the restoration process is disruptive to the system.
- High Risk Systems or data that if compromised (data viewed by unauthorized personnel, data corrupted, or data lost) would cause an extreme disruption in the business, cause major legal or financial ramifications, or threaten the health and safety of a person. The targeted system or data requires significant effort to restore or the restoration process is disruptive to the business or other systems.
Assign a risk level to each of the following: core network devices, distribution network devices, access network devices, network monitoring devices (SNMP monitors and RMON probes), network security devices (RADIUS and TACACS), e-mail systems, network file servers, network print servers, network application servers (DNS and DHCP), data application servers (Oracle or other standalone applications), desktop computers, and other devices (standalone print servers and network fax machines).
Network equipment such as switches, routers, DNS servers, and DHCP servers can allow further access into the network, and are therefore either medium or high risk devices. It is also possible that corruption of this equipment could cause the network itself to collapse. Such a failure can be extremely disruptive to the business.
Once you’ve assigned a risk level, it’s necessary to identify the types of users of that system. The five most common types of users are:
- Administrators Internal users responsible for network resources.
- Privileged Internal users with a need for greater access.
- Users Internal users with general access.
- Partners External users with a need to access some resources.
- Others External users or customers.
The identification of the risk level and the type of access required of each network system forms the basis of the following security matrix. The security matrix provides a quick reference for each system and a starting point for further security measures, such as creating an appropriate strategy for restricting access to network resources.
- Serial Offenders: Widespread Flaws in Serial Port Servers (icnmsolutions.wordpress.com)
- 10 Tips To Prevent Data Theft (thehartford.com)
- Use a Network Access Control policy to illuminate potential threat decisions (ibm.com)
- Verdasys and FireEye Partner to Stop Cyber Attacks (prweb.com)
- How the World’s Most Advanced Network Processor is Making the Internet of Everything Possible (blogs.cisco.com)
- IPAM is Essential to Network Management (blogs.cisco.com)