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Need some help please 1

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Sep 23, 2002
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Hi, I'm new to cisco routers + the routing thing and there are some things on a cisco router that i don't know what they are used for(or purpose they serve).

Console port: what is its purpose and what does it do?

Aux port: what is its purpose and what does it do?

Thanks.
Mrconfused



 
Console Port: this is where you plug in a console (for example, a PC running Hyperterm) to configure and troubleshoot the router.

Aux Port: serves a similar purpose (configuration and troubleshooting the router), but usually a modem is plugged into it for dial-in access.
 

Thanks, I heard that you can actually connect a modem to the console port if you have a certain adapter. Is this true.

Can you connect from one router's console to another router's/switches aux port? As to configure the second router/switch from the first?

Thanks,
Mr Confused
 
Yes and Yes


I do both of those all the time in my setups, like I take the console port of a router and hook to the modem, then from the aux port on the router to the console of a switch or another router...


Works very well.



BuckWeet
 
From what i've heard so far there really doesn't seem like there is much of a difference between the aux port and console port. Only difference I can see is that for the console you can attach a laptop to it and configure it but you can't do it on an aux port. And both ports can support modems.

So what factors help decide when you would use an aux port as compare to the console port?

Thanks again,
Mrconfused.
 
You certainly can configure a router from the aux port. It's just a nice extra to have. Most often, folks connect the console to a terminal or terminal server and a modem to the aux. But if properly configured, you can plug a terminal or terminal server to an aux port.
 
From Cisco's website.

Advantages of connecting a modem on the console port:
Passwords can be recovered remotely.
It is a convenient method of attaching a second modem to a router without async ports.
Some routers (for example, Cisco 1600s) do not have AUX ports.

Disadvantages of connecting a modem on the console port:
The console port does not support RS232 modem control (data set ready/Data Carrier Detect (DSR/DCD), data terminal ready (DTR)). Therefore, when the EXEC session terminates (logout), the modem connection will not drop automatically; the user will need to manually disconnect the session.
More seriously, if the modem connection should drop, the EXEC session will not automatically reset. This can present a security hole, in that a subsequent call into that modem will be able to access the console without entering a password.
Unlike other async lines, the console port does not support hardware (Clear to Send/Ready to Send (CTS/RTS) flow control. It is recommended to use no flow control. If data overruns are encountered, however, software (XON/XOFF) flow control may be enabled.
The console ports on most systems only support speeds of up to 9600 bps.
The console port lacks reverse telnet capability. If the modem loses its stored initialization string, the only remedy is to physically disconnect the modem from the router and attach it to another device (such as an AUX port or a PC) to reinitialize. If a modem on an AUX port loses its initialization string, you can use reverse telnet remotely to correct the problem.
A console port cannot be used for dial-on-demand routing; it has no corresponding async interface.

For further info,
 
Woot, thanks man, that cleared up a bit of the confusion for me. Now i can sit here and rack my brains out on other things heh

Thanks
mrconfused
 
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