What does line vty 0 4 mean in router or switch configuration?
When configuring a router or switch, we may encounter the terms "line vty 0 4" or "line vty 0 15". So what does line vty 0 4 and line vty 0 15 mean?
Now we're going to talk about vTY.
The term VTY is fully called Virtual teletype. A Virtual terminal is used to obtain Telnet or SSH access to a device. A VTY is only used for inbound connections of the device.
The abstract "0-4" indicates that the device can allow up to five virtual connections simultaneously, which can be Telnet or SSH. To some extent, we can say that 5 (0-4) is the connection port of a router or switch. In fact, we may have as many as 16 (0-15) connection ports.
Here is an example where we configure Telnet access to cisco devices and Telnet Settings for passwords
R3(config)#line vty 0 4 R3(config-line)#password Cisco R3(config-line)#login R3(config-line)#exit Copy the code
Above is cisco's configuration, let's take a look at how Huawei devices are configured.
[HUAWEI]user-interface vty 0 4 [HUAWEI-ui-vty0-4]authentication-mode password [HUAWEI-ui-vty0-4]set authentication passowrd cipher Copy the code
Configuration of H3C:
[H3C]telnet server enable [H3C]user-interface vty 0 4 [H3C-line-vty0-4]authentication-mode none [H3C-line-vty0-4]user-role level-3 Copy the code
In general, vTY configuration is very basic, I hope you can see it, do it, in daily work will not only configuration, but also know what vTY is in the end.