Re: What IOS really does with commands (was Re: ISIS Problem.

["Howard C. Berkowitz" <hcb@xxxxxxxxxxxx>]

At 6:17 AM +0000 3/29/04, loc.pham@xxxxxxxxxxx wrote:
> I am abit confused...
> How can we validate WYSIWYG ? addional sh ( ip route, access-lists, ... ) ?

If you are asking whether there is a way, using IOS alone to confirm 
what you typed in configuration mode, it doesn't exist. The only way 
to do that is to create the file in an editor, validate it there, and 
transfer that file to the router.

> So would you agreed that for the sake of RS lab, whatever that 
> 'supposed' to be display on the output of sh run would be sufficient 
> to verify our typing commands ?

Under lab constraints, it's probably the only practical way to do it. 
In the real world, I usually write my configurations with an editor. 
Sometimes I paste them to a telnet window, and other times they are 
file uploads from Telnet or possibly more involved scripts (e.g., 
expect).

> Would some rel. of IOS accept the commands, record it but ... do nothing ?

No.  The configuration editor parses the commands in real time. 
Depending on the command and whether it can be partially parsed as 
it's typed, the full line may never actually enter a buffer beyond 
that of the editor.