[PLUG] netfilter transparent mode (like SonicWall)

[Paul Heinlein]

On Fri, 6 Jun 2008, Tim wrote:

>> So anyone have suggestions as to where (specifically) to look for
>> methods of emulating a SonicWall with netfilter/iptables?
>
> Assuming I understand what you're asking, I'd say iptables does this 
> by "default" in a sense.  In order to implement NAT or NAPT, one 
> needs to use the nat table in iptables.  If you don't use this, then 
> your firewall will just act as a normal filtering router.  You just 
> need to set up your filter table rules in line with what your 
> routes/subnets are and what ports you want open.
>
> If you're actually talking about a bridging-mode firewall, netfilter 
> can do that too with ebtables, though I'm not sure if ebtables is 
> production-ready for what you're trying to do.  I've used it to 
> transparently filter access to VMs at the VM host level, but not for 
> full networks.

You might try reading "Bridgewalling - Using Netfilter in Bridge 
Mode":

http://www.spenneberg.com/talks/linux-kongress2002/ralf-spenneberg.bridgewall.pdf

-- 
Paul Heinlein <> heinlein at madboa.com <> http://www.madboa.com/