> When using the command 'copy running-config startup-config' you are
> presented with a filename choice. What format does this have to be in?
> Are spaces or alphanumeric characters allowed? What file name extension
> is used? Should I choose a descriptive name? When used through the GNS3
> simulator this is only going to save the file on the current router which
> is in the window correct? Thanks in advance.
Don't know about GNS3 but these links should explain Cisco file handling: