I work in a school and have just had our ADSL Broadband connection replaced with Fibre Internet service from BT. Previous to the upgrade we had a CISCO 1840 installed on which we had NAT and a Firewall enabled on.
BT have installed a CISCO 3825 Router which they state is fully managed by them, however, they will not provide / allow NAT for a firewall to be configured on this router.
Our config before was
217.x.x.x (Internet address)
192.168.1.x (CISCI 1840 Router with NAT & Firewall)
192.168.1.x (EXT Card on Web Server)
192.168.10.x (INT Card on Web Server)
ISA 2000 installed on Web Server
192.168.x.x (IP Range for LAN)
86.x.x.192 (IP Provided by BT)
86.x.x.193 (CISCO 3825)
86.x.x.194 (1st available / usable Public IP)
I need advice on how I should proceed with NAT & Firewall. Can you please advise on whether it would be best to purchase a hardware firewall with NAT in order to get the new settings to work securely along with my network or can I simply configure ISA 2000 to do this?
Would this put extra load on my server etc etc etc, please help?