Hardening Cisco Routers

Chapter 1. Router Security

In Webster’s dictionary the definition of hard is particularly relevant to the field of information security:

Not easily penetrated or separated into parts; not yielding to pressure.

By hardening a router, we make it difficult to penetrate and unyielding under the pressure of attacks. This chapter discusses why hardening network routers is one of the most important and overlooked aspects of Information Security. It will talk about what can go wrong when routers are left insecure and identify which routers are at the most risk from attack.

Router Security?

When asking about Information Security (InfoSec), most people immediately think about stolen credit cards, defaced web sites, and teenage hackers with names like B@D@pple. An InfoSec professional might extend the list to items like firewalls, Virtual Private Networks (VPN)s, penetration testing, and risk analysis. What is almost never listed is router security—network security, yes, but never specifically router security. The distinction is important.

Network security is most often thought of as something that protects machines on a network. To do this, companies put up firewalls, configure VPNs, and install intrusion detection systems. Router security, however, involves protecting the network itself by hardening or securing the routers. Specifically, it addresses preventing attackers from:

• Using routers to gain information about your network for use in an attack (information leakage)

• Disabling your routers ...