It’s possible your Internet service provider uses a non-routeable IP range (like 10.*) and occasionally your border device picks that up via DHCP by accident instead of an Internet address. If that happens to you, and you’re using DragonFly as your border gateway, it’s possible to prevent it with PF dhclient.
The May issue of BSD Magazine is out with a number of pf articles, plus others.
I am somewhat entertained by Michael W. Lucas’s most recent blog post about IP Sets. This is mostly because, as he points out, he could use one pf config file across multiple machines and BSDs for network management, but has to fiddle with ipsets to get different Linux machines to match.
DragonFly versions >=2.6 and ipfw don’t seem to get along for doing network address translations. I’ve posted about this before, but I’m linking again because this time I have the explicit config lines written out.
I should probably create a pf category…