Setting up PIX 506E/1751 Router

[EduardoA]

I need a little help setting up my company's network. I have a Cisco 1751 Router and a PIX 506E Firewall. I only have one Internet IP Address, which I want my internal network to use when going on the Internet. I know I will have to setup the PIX with PAT so my internal users can get out on the Internet. My question is, what should my IP addresses be for the rest of the network, LAN is using 192.168.0.X, I am not sure what IP addresses I should give to PIX’s External/Internal interface and the Router’s NIC connected to PIX’s external interface???????????


Router 1751 ---- PIX 506E ----- Switch -------
|
|
LAN


Router's IP:
NIC connected to service provider 206.172.X.X

NIC connected to PIX’s external NIC xxx.xxx.xxx.xxx ?


PIX’s IP: External xxx.xxx.xxx.xxx ???
Internal xxx.xxx.xxx.xxx ???

I am new to this, so any help would be greatly appreciated.

Thanks in advance,

Eduardo

 

[sunyasee]

The external pix address will have to be public, the internal address will be private so it will need to be part of the 192.168.0.X network (this will be the gateway address for your LAN machines). The outside address can also be used for PAT, so the LAN machines get this address when they go out on the internet. On the router you can use only one address if you configure the serial interface 'unnumbered'. Normally ISPs configure unnumbered links to save on IP addresses. For example..

interface serial0
ip unnumbered ethernet0

interface ethernet0
ip address X.x.x.x

So the serial interface uses the ethernet ip address. ----

Sunyasee B-)

 

[yizhar]

HI.

The right way to go is to acquire a range of ip addresses from your ISP, and not to use a single one.

If you don't go that way, you'll have to use PAT on the router which will limit some of your options like future use of VPN, and more.

Bye
Yizhar Hurwitz

http://come.to/yizhar

http://teachers.sivan.co.il/yizhar