Em 18/02/14 14:53, Mark Fox escreveu:
I've been waffling over a permissive or restrictive FORWARD chain and have realized that my understanding of the implications is lacking. So I'll just ask: What are the implications of a permissive FORWARD chain? My situation is that I am deploying a virtualization/containerization host at a facility that has one big network for everything (servers, desktop workstations, etc.). There is no DMZ. As one would expect, the network is really chatty. Traffic has to be forwarded to/from the VM/container host to/from the VMs or containers, so a DROP policy on the FORWARD chain means carefully crafting rules to allow traffic to be forwarded to the VMs/containers. I have no issues with that, but it does mean that the future users of the VM/container host would have to craft their own rules when they add new VMs/containers.
There's no right or wrong on how your FORWARD default rule should be. Being DROP or ACCEPT depends on your network security policies.
Being ACCEPT the default action for FORWARD, your linux router will forward anything from one side to the other, unless it's explicity DROPped on the rules. Being DROP the default action, everything will be dropped, except explicitely ACCEPTed by your rules.
Which one fullfit you demands ? So that's the right one for you ! No one can tell you, giving only the information you wrote, that DROP or ACCEPT is right or wrong. There's really no right or wrong here, there's what fullfilts your demands/needs and what doesnt.
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