Computer Network Security

2Securing Network Devices

This chapter studies the following topics:

• – the types of network traffic:
  • - the management plane,
  • - the control plane,
  • - the data plane;
• – securing the management plan:
  • - securing passwords,
  • - implementing connection restrictions,
  • - securing access through control lines, VTY and auxiliaries,
  • - assigning administrative roles: protecting access using privilege levels;
• – protecting access through the management of “views” and “super-views”:
  • - securing configuration files and the system,
  • - using automated security features;
• – securing the control plan.

2.1. Types of network traffic

Cisco has categorized the different types of network traffic into different “planes” of communication. It has defined three such planes: the management plane, the control plane and the data plane.

• – the management plane: this includes traffic used by a network administrator to configure network devices. It is generally made up of protocols, such as Telnet, SSH and SNMP;
• – the control plane: this includes traffic between the network devices, transmitted to each other for discovery and/or for automatically configuring the network, such as the traffic of updating routing protocols or ARP protocol, for instance.
• – the data plane: this is the actual traffic of end users in the network.

2.2. Securing the management plan

Securing the management plan includes, among others, the following:

• – applying a secure password policy;
• – securing console, VTY and auxiliary access; ...