The first change concerns the use of the 5.x.x.x address space. As you may or may not be aware, this address space has been allocated by IANA to RIPE NCC two years ago. RIPE NCC has been handing out these addresses to their customers, and having Hamachi active on your computer means that you’re not able to access a growing portion of the Internet. We’ve added IPv6 support to Hamachi a while back, and you can simply turn off the use of the 5/8 space, but we realize that IPv4 is still very important to most of you. Therefore we’ll be changing every Hamachi node’s address to the 25/8 space. The first octet of your Hamachi node’s IPv4 address will change from 5 to 25, the last three octets will be unaffected. If you’re using Hamachi with any sort of dynamic name resolution service (Bonjour, etc) you will not notice anything different. If, however, you use Hamachi IP addresses in scripts or, say, saved them in SSH client address books, you will need to change these and add the digit 2 in front.