One of the first things a security minded networker or administrator needs to do is secure administrative access to the network devices meaning routers, firewalls, switches, servers, etc. The CCNA Security curriculum goes much farther than the CCNA Exploration in explaining the different methods of securing access to network devices. In addition to the command line interface (CLI) it also covers other GUI management tools like Cisco Security Device Manager (SDM).
Packet Tracer is a fantastic tool provided to Cisco Academy students to learn how to configure and troubleshoot network devices. The following video tutorials cover the initial router configuration and how to secure access to both the local and remote management interfaces.
How to configure the console port (local access) and an IP address on the ethernet interface for remote access
How to configure the VTY ports for remote telnet access and configure the enable password for privileged user mode
How to enhance security by encrypting passwords with type 7 and md5 encryption
Begin AAA security protocols, by configuring usernames and passwords with md5 encryption
Configure minimum password lengths, exec login timeout time, and login block-for commands