How can you secure a Cisco router?

Securing a Cisco router is best achieved by implementing a combination of measures that enhance its security posture. Configuring strong passwords is fundamental, as weak or default passwords can be easily compromised. Strong passwords help to ensure that unauthorized users cannot gain access to the router's configuration.

Enabling SSH (Secure Shell) is another critical step. Unlike Telnet, which transmits data in plaintext, SSH provides a secure channel over an unsecured network by encrypting the data being transferred. This prevents attackers from easily intercepting and reading sensitive information such as passwords or configuration commands.

Applying access lists plays a vital role in controlling the traffic that can enter or exit the router. By defining specific rules, you can restrict access to the router’s interfaces based on IP addresses, protocols, or ports. This not only helps in blocking undesired traffic but also limits the potential attack surface by permitting only trusted sources.

Combining these three strategies significantly strengthens the router's defenses against unauthorized access and potential attacks, making it a robust approach to securing the device.