OS X Server 5 (El Capitan 10.11 or Yosemite 10.10) has an adaptive firewall built in, or a firewall that controls incoming access based on clients attempting to abuse the server. The firewall automatically blocks incoming connections that it considers to be dangerous. For example, if a client attempts too many incorrect logins then a firewall rule restricts that user from attempting to communicate with the server for 15 minutes. If you’re troubleshooting and you accidentally tripped up one of these rules then it can be a bit frustrating. Which is why Apple gives us afctl, a tool that interacts with the adaptive firewall. The most basic task you can…
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Changes in Mountain Lion Server
Mountain Lion Server is now available on the OS X App Store and as with the last few updates there are some things missing that you might be expecting and depending on. First up, three major services are gone: Podcast Producer, RADIUS and dhcp. You can still do dhcp as you always did with OS X client as those features work on OS X Server, but the more granular controls available in OS X Server are now gone. The biggest impact of dhcp is probably in testing NetBoot services when there are network issues and you need to prove to network admins that it’s the network and not your server……
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A Cheat Sheet For Using pf in OS X Lion and Up
I’ve done plenty of writing on the Application Layer Firewall (ALF) and the IP FireWall (IPFW) in OS X over the years. There will be more on ALF coming in “July” but in the meantime, there’s something I hadn’t written much about in Lion and that’s the pf implementation. To get started, let’s look at the /etc/pf.conf configuration file that comprises pf: scrub-anchor "com.apple/*" nat-anchor "com.apple/*" rdr-anchor "com.apple/*" dummynet-anchor "com.apple/*" anchor "com.apple/*" load anchor "com.apple" from "/etc/pf.anchors/com.apple" Here, you can see that pf is configured with a number of anchors. An anchor is a collection of rules and tables. Basically, the anchor file being loaded is /etc/pf.anchors/com.apple. In here, we…