Specifications

Overview of Dial Interfaces, Controllers, and Lines
Line Types
DC-14
Cisco IOS Dial Technologies Configuration Guide
Line Types
This section describes the different line types used for dial access. It also describes the relationship
between lines and interfaces.
Note Cisco devices have four types of lines: console, auxiliary, asynchronous, and virtual terminal.
Different routers have different numbers of these line types. Refer to the hardware and software
configuration guides that shipped with your device for exact configurations.
Table 3 shows the types of lines that can be configured.
Use the show line command to see the status of each of the lines available on a router. (See Figure 11.)
Table 3 Available Line Types
Line Type Interface Description Numbering Rules
CON or
CTY
Console Typically used to log in to the router for
configuration purposes.
Line 0.
AUX Auxiliary EIA/TIA-232 data terminal equipment
(DTE) port used as a backup (tty)
asynchronous port. Cannot be used as a
second console port.
Last tty line number plus 1.
tty Asynchronous Same as asynchronous interface. Used
typically for remote-node dial-in
sessions that use such protocols as SLIP,
PPP, AppleTalk Remote Access (ARA),
and XRemote.
The numbering widely varies
between platforms. This
number is equivalent to the
maximum number of modems
or asynchronous interfaces
supported by your access
server or router.
1
1. Enter the interface line tty ? command to view the maximum number of tty lines supported.
vty Virtual
asynchronous
Used for incoming Telnet, LAT, X.25
PAD, and protocol translation
connections into synchronous ports
(such as Ethernet and serial interfaces)
on the router.
Last tty line number plus 2
through the maximum number
of vty lines specified.
2
2. Increase the number of vty lines on a router using the line vty global configuration command. Delete vty lines with the no
line vty line-number command. The line vty command accepts any line number larger than 5 up to the maximum number of
lines supported by your router with its current configuration. Enter the interface line vty ? command to view the maximum
number of vty lines supported.