I am not a router expert, so please excuse any omissions in my list of information. I have a Cisco 1720 router that our company is using to provide Internet access to our users, pass mail to and from our Exchange server, and allow the outside to access our Web server through a T-1. I'm new to company, so I wasn't here when the router was setup. We currently have eight outside addresses and then NAT setup for the inside. The outside addresses are used for the router itself, our Web server, an FTP server, and outlook web, etc. I setup a VPN server, and need to give a couple of other servers outside IP addresses so that they can be accessed. Our ISP gave me eight more addresses, but of course I can't use them until I update the information on the router. I have a couple of questions:
1. To expand the IP range for the outside, do I just need to edit the line that starts ip nat pool internet...... Here's what I have now:
ip nat pool internet xxx.xxx.xxx.201 xxx.xxx.xxx.201 netmask 255.255.255.248
Do I just have to change it to:
ip nat pool interent xxx.xxx.xxx.193 xxx.xxx.xxx.193 netmask 255.255.255.240?
If I do that, and keep the router address at 201 where it used to be, is that a problem, since it's in the middle? I guess I could change it, since my users see the inside address of the router as the gateway, but what are the ramifications of doing that on the outside? Will I lose my current source list that I have (ip nat inside source static outside address inside address)?
2. I'm not sure if I've been given a new DNS server to use with this configuration change. How to I tell?
I realize these may be newbie questions. I just don't want to mess up the router and be innundated with screaming users!
1. To expand the IP range for the outside, do I just need to edit the line that starts ip nat pool internet...... Here's what I have now:
ip nat pool internet xxx.xxx.xxx.201 xxx.xxx.xxx.201 netmask 255.255.255.248
Do I just have to change it to:
ip nat pool interent xxx.xxx.xxx.193 xxx.xxx.xxx.193 netmask 255.255.255.240?
If I do that, and keep the router address at 201 where it used to be, is that a problem, since it's in the middle? I guess I could change it, since my users see the inside address of the router as the gateway, but what are the ramifications of doing that on the outside? Will I lose my current source list that I have (ip nat inside source static outside address inside address)?
2. I'm not sure if I've been given a new DNS server to use with this configuration change. How to I tell?
I realize these may be newbie questions. I just don't want to mess up the router and be innundated with screaming users!