How to change several parameters in cisco?

Question

Cisco

We have cisco asa 5505.
It is located for 3/9 of the earth and I can only connect to it via ssh
. The local provider has conceived an IP change. And now I need to change its IP, gateway, rewrite routes.
The problem is that as soon as I change at least one parameter, the connection will be interrupted.
How to change all parameters at once, without saving the settings to flash?
Just suddenly something will not work, so that you can return everything as it was with a reboot. (there is a specially trained person who knows how to turn it off from the socket)
There is no way to organize access from the inside, since a specially trained person has my asa the only access to the Internet.

Answer 1

1. Turn on the healthy paranoia mode and forget the bare tftp / ftp
3. Save the current config, copy it to the computer.
Preparing a config file. Drive commands into it, as if you were in the console and configure the piece of iron in config-mode. That is, if you want to change the ip on the interface, write:
int gig1/0/1
no ip add
ip add 1.1.1.1 255.255.255.252
if you want to change the route:
no ip route
ip route $something
I think you understand. The main thing is to anticipate how the ASA will react to commands and remember to take this into account in the file.
2. ASA must support scp. Here is a guide on how to set up and upload the config file
3. In case of an error and loss of access, we plan to reboot in 10 minutes:
# reload in 10
4. Just activate the changes:
#(config) copy flash:changes.txt running-config
5. Check the result. If unsuccessful, the ASA will reboot on the old startup-config and it will be possible to correct the errors and repeat the procedure.
If, for some reason, scp does not work, you can copy the change file via tftp via easyVPN (which will need to be raised between the workstation and the ASA), but that's another story

Answer 2

As an option, merge the config via tftp, change it and upload the changed back. If everything is OK, do wr.