On Sat, 24 Nov 2012, Sabahattin Gucukoglu wrote:
http://b.logme.in/2012/11/07/changes-to-hamachi-on-november-19th/
LogMeIn Hamachi is basically a NAT-traversing layer 2 VPN solution. They
avoided conflicts with RFC 1918 space by hijacking IPv4 space in 5/8, now
actively being allocated by LIRs in Europe. When that didn't work (see link
above), they moved to 25/8, allocated to the UK MoD. While I'm almost sure
that they haven't got it quite so wrong this time, following the comments says
that the idea was not only a very bad one to start with, it's cost a lot of
people a lot of grief that IPv6 was clearly going to mitigate in renumbering.
Perhaps it is why they recommend it per default, if not for the number of
applications that would be broken by it.
Both TMobile in the US, and Rogers/Fido in Canada use 25/8. Our IPsec
client per default only allows incoming NAT-T for ranges in RFC1918, due
to security reasons (you don't want them hijacking google's ip range). So
we actually had to add 25/8 to the white list a few years ago.
But, it would be nice to have an IPv4 range dedicated to VPN ranges, so
you can setup things like L2TP tunnels without fear of collision in the
RFC1918 space, although I guess technology has advanced enough to
implement proper segmentation and workarounds for this these days.
Paul