The most common way to mange a network device is via the command line interface (CLI).
One of the biggest flaws with managing a network this way is the possibility of misconfiguration through human error.
There are number of pros and cons to a command line interface
Pros can be that the command line interface is well known and understood, is commonly used and commands can be scripted where needed, syntax help is available on every command and connection the command line interface can be encrypted.
Cons of the command line interface is it is difficult to scale, there are a large number of commands and a knowledge of IOS is required, executing commands cna be slow, not intuitive with only one command executable at a time. CLI and commands can change between versions and the CLI can even pose a security threat if using telnet.