topic Re: Static NAT in Network Security

Static NAT

img — Mon, 11 Mar 2019 10:58:27 GMT

I wonder that can we configure Time based Static nat i.e During Office hours my private IP to be natted to a Public IP but after office hours the IP should be natted to a diffrent public IP ? is it possible any ways ?

Re: Static NAT

rajbhatt — Thu, 16 Aug 2007 05:18:27 GMT

Hi,

You can use time based access lists for control

http://www.cisco.com/en/US/docs/security/asa/asa72/command/reference/a1_72.html#wp1444018

but nat cannot be done based on time instead u could try using policy nat if that solves ur purpose using

source and destination address but here time based access lists will not be supported

http://www.cisco.com/en/US/docs/security/asa/asa72/configuration/guide/cfgnat.html#wp1042553

Raj

Re: Static NAT

Jon Marshall — Thu, 16 Aug 2007 06:09:38 GMT

As previous poster said you cannot do NAT based on time but it would be relatively easy to write a script that logs onto your firewall, clears the xlate for that static and then sets up a different static translation.

Jon

Re: Static NAT

img — Thu, 16 Aug 2007 11:13:18 GMT

Can you please provide me a sample script ?

Re: Static NAT

Jon Marshall — Thu, 16 Aug 2007 11:44:20 GMT

I will try and dig one out that i did a while back to do a similiar sort of thing.

Couple of questions

1) Are you familiar with Tcl/TK

2) Are you familiar with Perl

Do you have a linux/unix box to run the script from or will it be a windows box.

Jon

Re: Static NAT

img — Thu, 16 Aug 2007 11:59:06 GMT

nup i am not familer with both the scripting you mentioned but just provide me sample script, my look out to understand it.

Thanks in advance!

Re: Static NAT

img — Thu, 16 Aug 2007 12:00:01 GMT

it will be a windows box where i would like to run the script from!

Thanks very much

Re: Static NAT

Jon Marshall — Thu, 16 Aug 2007 12:04:44 GMT

Okay, no problem. As it's windows it might take a bit of time to dig out so bear with me.

Jon

Re: Static NAT

srue — Sat, 18 Aug 2007 02:40:58 GMT

You can install perl on windows (aka activeperl). You will also need the Windows version of the net::telnet & net::telnet::cisco modules. Adjust passwds and IP accordingly. Once you have the script working, just schedule it using windows.

=================================

#!/usr/bin/perl -w (adjust this accordingly)

use Net::Telnet::Cisco;

$passwd = 'telnet_passwd';

$enable_passwd = 'enable_passwd';

$pix = '192.168.1.1';

{

my $session = Net::Telnet::Cisco->new(Host => $pix, Timeout => 30);

$session->prompt('/[\$%#>] $/');

$session->login('pix', $passwd);

$session->enable($enable_passwd);

$session->cmd("conf t\nno static (inside,outside) 10.10.10.10 10.10.10.10\nstatic (inside,outside) 11.11.11.11 10.10.10.10");

}

==============

i've never configured a PeRL script to use ssh, but i suppose its possible.