Final answer:
The transport input ssh command allows SSH access on the switch vty lines for secure, encrypted connections. It does not enable Telnet, configure SNMP, or update routing tables.
Step-by-step explanation:
When the transport input ssh command is entered on the switch vty lines, it configures the switch to allow Secure Shell (SSH) access to the device. This command specifies which protocols can be used to connect to the switch via its Virtual Terminal lines (VTY). By setting transport input ssh, you are explicitly enabling SSH and, by default, disabling other means of remote command line access, such as Telnet, until they are explicitly enabled as well. Enabling SSH is a security best practice as it provides a secure, encrypted connection, in contrast to Telnet, which sends data in plain text. SNMP configuration, updating routing tables, or enabling Telnet access are not affected by this command.