Below is a hands-on lab using the SSH protocol to manage routers. It’s a practical little skill that comes in handy in real-world scenarios. The network topology consists of an SSH server R1 connected to an SSH client router R2, with an SSH client PC bridged in between.
1. Telnet is simple 鈥?just set a password and login to gain access. But Telnet isn’t very secure. I’ve done an SSH login setup experiment before, but I seem to have forgotten it lately, so let’s review it again here.
2. First, set up two routers connected directly, then add a PC bridged to both routers. Configure their IP addresses and ping-test to make sure everything works. This also helps establish some common sense and tips for learning other network configuration techniques down the road.
3. On R1, configure a hostname and define a domain name. These two steps are mandatory before enabling SSH because they are used during key generation. Then use the crypto command to generate a 1024-bit key. The router automatically creates a public key and a private key. At the same time, create a user and password on R1.
4. Enter the line vty interface configuration, specify that only SSH hosts are allowed to log in 鈥?no other access methods permitted. Then set the authentication to login local for local identity verification.
5. At this point, you can first test the login using an SSH tool on the PC. Note that you can select SSHv2, because we generated a 1024-bit key, and SSHv2 requires a key length of 768 bits or greater. The first time you connect, a dialog will pop up asking you to accept the public key. As long as that dialog appears, it proves