Dual setup for internet and internal access

Question

Goal: To set up an Xserve that is both hosting public web sites and internal websites. The server is currently connected to the internet via ethernet 1 and to our internal network via ethernet 2. It serves as a backup failover for our main web server and hosts an internal wiki. The wiki is getting more sensitive company information so we want to cut it off from outside access and guarantee that it cannot be hacked or otherwise seen. Someone mentioned a solution using partitioning of some kind to achieve this separation. I haven't been able to find information on this. Can anyone tell me more about what this may be or suggest a setup that will accomplish the same security.

Answer 1

Here, you have two NICs within one security context.
A security breach made via one NIC can generally gain access to another NIC within the context of a single operating system. Once the [security of the box is breached|http://labs.hoffmanlabs.com/node/1214] sufficiently to cause you problems (whether data exposures, deletions, defacement or otherwise), then the entire box is generally considered to be untrustworthy.
If the breach arrives via http port 80 (and that is a typical web server breach), then (once the breach is made) the box itself is compromised. The firewall block here doesn't get you the degree of isolation provided by a DMZ; a breach via port 80 inward or one of these recent browser-based attacks on the firewall aren't necessarily blocked. (Whether the particular web environment is directly vulnerable to a breach is another and open question. Some environments can be more vulnerable to others, but there's the common assumption that all web-facing and internet-facing environments can potentially be vulnerable. That also ties back to how the box is managed and monitored, and how fast a breach can be detected and isolated and sealed and cleaned up.)
Some operating systems feature technologies known as sandboxes or jails or such, and sandboxes (and jails) are not AFAIK officially available on Mac OS X Server. These are part-way between the default configuration and what's provided by operating as a VM guest. If you really want to learn the innards of the configuration sufficiently, you might be able to get a jail or sandbox or such going, but then tossing another Mac Mini at the problem solves it in what is usually a more supportable fashion than getting a sandbox or jail going and maintaining the configuration over Mac OS X Server patches and upgrades, and application installations and upgrades, and thus at lower cost.
The approach using a VM tries to avoid extending the exposure by requiring the attacker to breach the underlying VM to get further from the box, and approaches based on a DMZ and on multiple boxes also try to contain or firewall a compromised system.