By default, when you access a Cisco router for management purposes (using Console, Telnet or SSH) there is no username/password authentication required. You only need to supply the “privileged EXEC” password (i.e the “enable” password) in order to gain access to the full configuration mode of the router. Employing an additional level of authentication (i.e requiring the user to supply an additional username/password credential in addition to the “enable” password) will make the router device more resistant to unauthorized access. Moreover, configuring local usernames on the device gives you the flexibility to add granularity regarding the levels of management privileges for different users. For example, you can configure a username on the router with full privileges (privilege level 15) who can configure anything on the router, or you can configure a username with unprivileged access (privilege level 1) who can only see a few things on the router and nothing else.

There are two steps involved to configure local usernames. The first one is to create the username/password and assign it a privilege level (from 1 to 15, with 15 being the most privileged level). If you don’t specify a privilege level number, it gets the full privilege 15 by default. The second step is to configure your VTY lines (0 to 4) to require a local login access (i.e only a configured user with a valid password can access the router).

Configuration

Router# config t
Router(config)# username Mynetworkadmin privilege 15 secret $Str0ngP@ss$
Router(config)# username Onlymonitoring privilege 1 secret An0ther!Pass34

Router(config)# line vty 0 4
Router(config-line)# login local
Router(config-line)# exit
Router(config)# wr

Just a security tip here, for username select something difficult to guess or something that will not be found in dictionary attacks. For example, words like “admin”, “administrator”, “cisco” etc are not good usernames. A simple dictionary attack from a hacker will find those easily.

Related posts:

1. Password Security for Cisco IOS Devices
2. Cisco Router Password Recovery-How to recover cisco router lost password
3. CCNA Certification Exam Preparation Topics Part 2 – Router Passwords
4. Configuring PPPoE for Cisco Router 520 and for series 850 and 870
5. Cisco IOS Router Operation-CCNA Exam Prep
6. Configuring NAT on Cisco IOS Routers
7. Configuring Cisco Router Interfaces