求大家帮忙解释下TTY的意思，尤其是在cisco中是怎么表现的

wangbin2010jy

看了点资料有点模糊，自己感觉是通过物理线路的串行通信，console是其中的一个，那么cisco中还有其他的表现方式吗？谢谢，我自己进入这个配置模式，成这样的

a49410335

What's a CTY port?

The console port shouldn't need any introduction. The CTY port is, of course, where you configure the router when it's brand-new — before it has any IP address configuration. The console port is a serial port, so you must have a PC/laptop with a serial interface and connect to the console with a rolled cable, most likely, using a DB9 to RJ45 adaptor to connect from the serial port on your computer to the console port.

Once you've used the console port to configure the router's network configuration, it isn't common to have to use it again. However, it's good to know that it's there if anything ever goes wrong. In addition, you should secure the console port to keep someone from connecting to it when you aren't around.

What's the AUX port?

While not all routers these days have an AUX port, the AUX port is the auxiliary. Think of it as a secondary console port. The AUX ports don't get a lot of use except to access the router if locked out of the console port.

In the past, network admins would connect modems to the AUX ports so they could dial into their routers. Like the console port, the AUX port is a serial port, and you should also take steps to secure it.

What are TTY lines?

To have a TTY line on your router, you must have an ASYNC card in your router. This card provides some number of asynchronous serial ports on the router, which you can use for serial printers, serial modems, or dumb ASCII text terminals. With those ports, the serial printers could become networked printers (using the LPD service on the router), and the dumb terminals could become networked Telnet devices.

In the case of the router shown above, it has a 32-port asynchronous serial card (Cisco NM-32A ) installed, and it's using many of those ports for asynchronous serial devices such as ASCII text printers and ASCII test dumb terminals. This may seem archaic, but many companies still use this approach to connect to legacy UNIX systems to run legacy text-based applications. However, networked terminal emulators are slowly replacing them.

What are VTY ports?

VTY ports are virtual TTY ports, used to Telnet or SSH into the router over the network. You can use them to connect to the router to make configuration changes or check the status. Most routers have five VTY ports, numbered 0 to 4.

That means you can have up to five concurrent network admins configuring the router at one time. However, you can easily generate more VTY lines.

For example, to create a total of 21 VTY lines (numbered 0 through 20), enter the following:

Router (config)# line 0 20一共就这几种，有你看过的，也有你没看过的

senchuanaa121

。。。第一次见TTY。。。以前只见过VTY。。。。同求大神来解释

yanzijiangjun

The name of TTY actually comes from the old days of computers. At that time, computers had teletypewriters as terminal, so you could see the output of programs printed (tty = TeleTYpe/TeleTYpewrite). TTY usually refers for "physical" terminals, like more attached terminals (even like a teletypewriter) to a single computer, or in our days: more separated text consoles, you can switch between them Ctrl+Alt+F1-F7 in OS like Ubuntu,Redhat and so on. Please refer below sample:

TTY sample in Linux:
root@ubuntu:~# who
monica   tty4         2015-07-27 04:14
root     tty2         2015-07-27 04:14
andy     tty3         2015-07-27 04:14
billy    tty1         2015-07-27 04:16
billy    :0           2015-07-27 04:12 (:0)
billy    pts/7        2015-07-27 04:13 (:0)
root@ubuntu:~#

TTY config sampla in Cisco 2801:
C2801(config)#line tty 1 2
No physical hardware support for line 2
C2801(config)#line tty 1  
C2801(config-line)#?
Line configuration commands:
  absolute-timeout            Set absolute timeout for line disconnection
  access-class                Filter connections based on an IP access list
  activation-character        Define the activation character
  autobaud                    Set line to normal autobaud
  autocommand                 Automatically execute an EXEC command
  autocommand-options         Autocommand options
  autohangup                  Automatically hangup when last connection closes
  autoselect                  Set line to autoselect
  buffer-length               Set DMA buffer length
......

Rockyw

路过了解一下

大同IT男

我是英盲啊~~·