Book Image

CCNA Routing and Switching Complete Study Guide: Exam 100-105, Exam 200-105, Exam 200-125 - Second Edition

By : Todd Lammle
Book Image

CCNA Routing and Switching Complete Study Guide: Exam 100-105, Exam 200-105, Exam 200-125 - Second Edition

By: Todd Lammle

Overview of this book

CCNA Routing and Switching Complete Study Guide, 2nd?Edition?is your comprehensive review for the CCNA exams. Written by the leading authority on networking technology, this guide covers 100% of all objectives for the latest ICND1, ICND2, and CCNA Composite exams. Hands-on labs help you gain experience in critical procedures and practices. The CCNA certification is essential to a career in networking, and the exam can be taken in two parts or as a composite. Whichever you choose, this book is your essential guide for complete review. Full coverage and expert insight make?CCNA Routing and Switching Complete Study Guide?your ultimate companion for CCNA prep.
Table of Contents (7 chapters)

Appendix C
Disabling and Configuring Network Services

By default, the Cisco IOS runs some services that are unnecessary to its normal operation, and if you don’t disable them, they can be easy targets for denial-of-service (DoS) attacks and break-in attempts.

DoS attacks are the most common attacks because they are the easiest to perform. Using software and/or hardware tools such as an intrusion detection system (IDS) and intrusion prevention system (IPS) tools can both warn and stop these simple, but harmful, attacks. However, if we can’t implement IDS/IPS, there are some basic commands we can use on our router to make them more safe. Keep in mind, though, that nothing will make you completely safe in today’s networks.

Let’s take a look at the basic services we should disable on our routers.

Blocking SNMP Packets

The Cisco IOS default configurations permit remote access from any source, so unless you’re either way too trusting or insane, it should...