On 08/12/2014 08:37 AM, Jiri Popelka wrote:
On 08/06/2014 09:45 AM, David Andrew Michael Noelle wrote:
question 1 Do I have to do something more to /enable/ routing between the two localnets?
Does it change if you add masquerade into 'work' or 'dmz' ?
Indeed, adding Masquerade to 'work' allows anything in 'dmz', or subnets off of 'dmz', to browse the web server on a machine in 'work'. This does not look particularly secure to me. Does it not also allow the same forwarding, potentially, from 'external' to 'work'?
I found that direct rules in the FORWARD_direct chain also work, but are rather a hassle. Given the choice between all, nothing, or a bit of work to get one port open now and then, I'll be sticking with nothing until individual needs rise. Fortunately, in this case, not allowing communication between the localnets was the whole point of separating them in the first place.
question 2 How exactly are zones applied?
https://bugzilla.redhat.com/show_bug.cgi?id=1097960#c1 might shed some light on this.
Thanks. That does help. And I see Scott Shambarger had similar concerns about allowing too much forwarding.
question 3 What are the recommended methods of blocking specific localnet addresses or the whole "work" zone from connecting to specific ports on external host ranges, i.e. no FaceBook at work? Would rich rules in the "work" zone be the proper way?
We AFAIK don't have a way how to restrict outbound traffic, so I guess 'direct' rules are the only way.
Okay. It's not very dynamic, but neither was our old solution. This is a mite more complicated to edit, though. I see something on the Fedora wiki about "planned" saving of direct rules? Does that mean that there are plans to write direct.xml from firewall-cmd, but it's not available yet? If I were to write a script to read lists of external IPs and ports to block traffic to, I suppose I should have it invoke firewall-cmd to set the direct rules after firewalld is running rather than have it overwrite direct.xml before firewalld starts. That way wouldn't interfere with future direct rule saving, right?
question 4
Is there a way to specify classes of destinations, like a destination zone? It would be nice to bundle up the ip ranges or even domains of FaceBook and Twitter and Tumblr and whatnot into a "SocialMedia" class and just block any traffic to those destinations, either from the "work" zone or from specific localnet IPs.
Sounds like ipsets might come in handy here: https://lists.fedorahosted.org/pipermail/firewalld-users/2014-July/000201.ht...
Hmm. That does look like what I was looking for. Thanks. I'll read up on that.