9
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VTY (virtual type terminal) user interface: Used to manage and monitor users that log in via VTY. A
VTY port is a logical terminal line used for Telnet or SSH access.
Users and user interfaces
Only one user can use a user interface at a time. The configuration made in a user interface view applies
to any login user. For example, if user A uses the console port to log in, the configuration in the console
port user interface view applies to user A; if user A logs in through VTY 1, the configuration in VTY 1 user
interface view applies to user A.
A device has one console port, one AUX port, and multiple Ethernet interfaces. These user interfaces do
not associate with specific users. When a user initiates a connection request, the system automatically
assigns an idle user interface with the smallest number to the user based on the login method. During the
login, the configuration in the user interface view takes effect. The user interface varies depending on the
login method and the login time.
Numbering user interfaces
User interfaces can be numbered by using absolute numbering or relative numbering.
Absolute numbering
Absolute numbering identifies a user interface or a group of different types of user interfaces. The
specified user interfaces are numbered from number 0 with a step of 1 and in the sequence of console,
TTY (not supported, but the numbers are reserved), AUX, and VTY user interfaces. You can use the
display user-interface
command without any parameters to view supported user interfaces and their
absolute numbers.
Relative numbering
Relative numbering allows you to specify a user interface or a group of user interfaces of a specific type.
The number format is “user interface type + number”. The following rules of relative numbering apply:
•
Console ports are numbered from 0 in the ascending order, with a step of 1.
•
AUX ports are numbered from 0 in the ascending order, with a step of 1.
•
TTYs are numbered from 1 in the ascending order, with a step of 1.