Line/Int & Telnet Q

Ehron

Hello, I am new here. Studying for the intro.

Can anyone explain why you use "interface" for ethernet and serial connections, but "line" for console and telnet?

Also, is the nomenclature for telnet always "vty 0 4" ? If so, could you tell me why?

Thanks.

viper75

You use "Interface" for an Ethernet and Serial ports because they are physical Interfaces on the Router or Switch. There are also logical interfaces that do not physically exist.

The Interface command brings you (admin) to the interface you want to Configure. Serial\Ethernet\Fasthernet\ or Vlan. You can find detailed info. about this here: http://www.opennet.ru/soft/cisco-configuration.html

You use line for either:
con 0
vty 0 4

What this does is lets you configure some kind of local or remote management on the router or switch. The line con 0 is to configure access to the device through the console port on the back of the router\switch. This is only done locally thorugh a rollover cable.

The line vty is to configure telnet access to the router\switch. Meaning that if you're in California and you need to look at a router's routing table in New York you can just telnet to the router in New York AS LONG as you have the IP address of the device and the username and password.
What the "0 4" means is that you can have 5 telnet connections at the same time on this line.

****If you do not have vty 0 4 configured you will not be allowed telnet access to your router\switch. ****

Hope this kind of helps. I'm not the best person to explain this stuff, but I know it.

Con 0 is not considered and interface.
vty 04 is a logical connection (does not physically exist.)

Click on this link...this should help you out.
http://www.techexams.net/technotes/ccna/basic_router_management.shtml

Ehron

Thanks. That helped a lot.

Logically it seemed like the console connection should be an interface. This will help me remember it is not considered to be one.

viper75

dmaftei

Ehron wrote:

Also, is the nomenclature for telnet always "vty 0 4" ? If so, could you tell me why?

No. "vty 0 4" refers to a range of vty lines, in this case five: vty0, vty1, vty2, vty3 and vty4. You use "vty 0 4" when you want to configure the four vty lines identically.