The Cisco IOS software often sends unsolicited messages, such as a change in the state of a configured interface. Sometimes these messages occur in the middle of typing a command. The message does not affect the command, but can cause the user confusion when typing. To keep the unsolicited output separate from the typed input, the “logging synchronous” command can be entered under line configuration like line console 0 or line vty 0 4...
Disabling Domain Lookup
By default, when a host name is entered in enable mode, the router assumes that the user is attempting to telnet to a device. The router tries to resolve unknown names entered in enable mode by sending them to the DNS server. This process includes any words entered that the router does not recognize, including mistyped commands. If this capability is not wanted, the “no ip domain-lookup” command can be entered in global configuration mode to turn off this default feature.