Encryption and Filtering– Cisco Security Tools
Stateful and contextual packet filtering rely on information within packets to protect servers and applications, but what if the packets in a stream are encrypted? Encryption prevents middleboxes, including firewalls, from effectively seeing the information needed to filter based on …
Defensive Tools and Design– Cisco Security Tools
The network often provides the first—and sometimes the only— layer of defense for network-connected devices. This section explains stateful packet filtering, contextual packet filtering, the firewall, source address validation, and defensive layering. Stateful and Contextual Packet Filtering Network security’s “pointy …
Two-Factor Authentication (2FA)– Cisco Security Tools
As mentioned earlier, three factors are used to authenticate a user: • Something you know • Something you have • Something you are Passwords and passphrases are something you know. Because people often create easy-to-guess passwords or are sometimes compromised, …
Strong Passwords– Cisco Security Tools
Security systems can rely on three things to prove a user is who they say they are: something they know, something they have, and something they are. Passwords and passphrases are something you know. A password is a set of …
Authentication Tools– Cisco Security Tools
Chapter 19 began the authentication discussion with authentication, authorization, and accounting (AAA) tools. This section extends the authentication discussion with important concepts like single sign-on (SSO ) and zero trust. None of these authentication systems are foolproof, however; they all …
“Do I Know This Already?” Quiz– Cisco Security Tools
Take the quiz (either here or use the PTP software) if you want to use the score to help you decide how much time to spend on this chapter. Appendix A, “Answers to the ‘Do I Know This Already?’ Quizzes,” …
Packet Captures–Cisco Troubleshooting
The case study in the previous section used only the ping command to capture information about the network. What if the problem were host A’s connection to server X is slow, while D’s connection to server X is performing normally? …
Advice to Troubleshooters–Cisco Troubleshooting
Troubleshooting is a difficult skill. It is easy to become tangled up in trivia or chase the wrong set of symptoms, and it takes far longer to find and fix a problem than it might seem it should. This section …
“Do I Know This Already?” Quiz–Cisco Configuring a Network
Take the quiz (either here or use the PTP software) if you want to use the score to help you decide how much time to spend on this chapter. Appendix A, “Answers to the ‘Do I Know This Already?’ Quizzes,” …
Foundation Topics–Cisco Configuring a Network
This chapter works through the process of configuring the network shown in Figure 23-1. Figure 23-1 Sample Network Note Previous chapters considered configuring hosts. Because of this, A, B, and C will largely be ignored from a configuration standpoint throughout …