Ok, I might be a newbie to opnsense (been around since before html) but I came across and entry in my liveview this am that I've never come across before - 64.225.77.0 (yeah yeah DigitalOcean). I have never come across a '.0'. I always thought .0 and .255 were reserved. Are they hiding their actual ip? Also had a.255 from another hosting company (Hetzner) yesterday too. Can someone shed some light on this please.
TIA
Giz..
.0 and .255 are just the boundaries of a /24 subnet, and as well of all smaller subnets and in these ones they are used as network and broadcast addresses in. But there are many wider subnets used out there.
The Digital Ocean network is 64.225.76.0/23. So its network address is 64.225.76.0 and its broadcast is 64.225.77.255. Hence 64.225.77.0 is in the middle of their subnet and can used for any other pupose.
"Reserved" is but a convention. Also, in this case, the IP lies with the 64.225.64.0/20 range (https://ipinfo.io/AS14061/64.225.64.0/20).
Because of CIDR, with "C" meaning "classless", the netmasks do not need to be /24 as you might expect. In that specific /20 range, 64.225.77.0 is just an arbitrary address within the range, nothing special about it.
Well I'll be dammed, Thanks viragomann & meyergru for keeping it simple for an old guy like me.