Firewall Wizards mailing list archives
Re: Maximum number of subnets on a firewall
From: Chuck Swiger <chuck () codefab com>
Date: Sat, 31 Jan 2004 15:23:33 -0500
Paolo Supino wrote:
The following story and question aren't product specific so please don't try to attach it to any available product: I was asked to plan a network for a group of 3 companies (all located in the same building and want to use the same infrastracture). From gathering the requirements of each of the companies I've concluded that all of them together will need 10 subnets (including the subnet that is connected to the internet). Since the biggest number of subnets per firewall that I ever installed was 6. Setting up 10 subnets on 1 firewall (to me) seems too much for me so I'm looking for a way to have the 10 networks on 2 (or 3) different firewalls. If you have any suggestions on a possible layout I'd be very happy to read it.
Frankly, unless two companies really trust each other and have the same security policy, they should not attempt to share a firewall, and of course, you want something between your upstream network connection(s) and your shared DMZ infrastructure zone.
At the least, this means you should be looking at: inet1 ----> +-----+ +-----+ <===> [ Company A subnet 1], [A2] | fw1 | <===[DMZ]===> | fw2 | <===> [ Company B1 ], [B2], ... inet2 ----> +-----+ +-----+ <===> [ C1 ], [C2], ... Otherwise, add another one or two firewalls for company B or C: | | V V [ fw3 ] [ fw4 ]...attached to the DMZ, as well. Your DMZ could be as simple as a 4-port hub or switch, or you could put shared resources like nameservers, mailservers, a web proxy server, etc.
-- -Chuck _______________________________________________ firewall-wizards mailing list firewall-wizards () honor icsalabs com http://honor.icsalabs.com/mailman/listinfo/firewall-wizards
Current thread:
- Maximum number of subnets on a firewall Paolo Supino (Jan 31)
- Re: Maximum number of subnets on a firewall Paul Robertson (Jan 31)
- Re: Maximum number of subnets on a firewall Devdas Bhagat (Jan 31)
- Re: Maximum number of subnets on a firewall Chuck Swiger (Jan 31)
- RE: Maximum number of subnets on a firewall Bill Royds (Jan 31)