Firewall for real IP's

[Gecko68]

They're asking me to set up a firewall here at work, and I want to make sure this is possible with the configuration that I have.
An ISP colocates the T1/router/portmaster/switch setup here, but They will give us a dedicated Ethernet port out of the back of the router for just our use, which will be configured to route the IP's from our network. Those IP's are actual live public IP's. What I'd like to do is have a firewall/router between the cisco router and our LAN of public IP's:

T1-->CiscoRouter-->Firewall-->HPSwitch-->LAN

I was originally planning on converting our LAN over to a private IP configuration, but have ruled that out, per The Boss. I did successfully set up a firewall on a 486 running RH6.1 with the 2.2.16 kernel using ipchains on the private subnet. Will that same general firewall config work with public IP's as well as private IP's?

Any suggestions/comments/helpful hints are more than welcome! http://www.linuxnewbie.org/ubb/smile.gif



------------------
Windows 2000: You, too, can cause a Blue Screen Of Death by writing to a FLOPPY DISK!!!!!

[Craig McPherson]

Yes, it's possible. You set the firewall up as normal EXCEPT you don't use IP Masquerading. Nothing else changes.

------------------
http://users.ipa.net/~cmcpher/paminv.gif DEBIAN (http://www.debian.org/) http://users.ipa.net/~cmcpher/paminv.gif
It turns girls into statues!

[This message has been edited by Craig McPherson (edited 30 November 2000).]

[Craig McPherson]

Well, not to say that "nothing" else changes. Do a sanity check of all your rules. Basically you'll need to forward any input that's aimed at your IP address range your entire real IP address range, rather than masquing stuff aimed at a singular IP address like you'd do with a single-IP masq setup. But not too difficult, though.

[Gecko68]

Thanks! http://www.linuxnewbie.org/ubb/smile.gif that just lowered my stress level considerably. I was hoping it would be something along those lines, but I keep getting interrupted every time I sit down and try to look up some more info on the subject.

wow! I just noticed the bottom half of the window, and it scrolls the previous page. Hadn't noticed that before. I like it.



------------------
Windows 2000: You, too, can cause a Blue Screen Of Death by writing to a FLOPPY DISK!!!!!