Networks created within the openstack platforms are not routed trough NTNU, thus in theory it is not important which subnet is selected. It might however be a problem if your virtual machine needs to contact external resources and you have provision your virtual machines within the same address range that is currently being use elsewhere, causing your local address range to overlap with the address range of another network. Because of this, it is common practice to use the address ranges specified in the RFC1918 (a.k.a IPv4 Private Address Space):
- 10.0.0.0/8
- 172.16.0.0/12
- 192.168.0.0/16
RFC1918 within NTNU
NTNU is however using the following subnets within the RFC1918 range, therefore their use should be avoided:
10.0.0.0/8 - Large pieces of this range is already in use; and this block is likely to be used in new subnets within NTNU as well. It is thus recommended not to use this block at all:
Broadcast 10.255.255.255 HostMin 10.0.0.1 HostMax 10.255.255.254 Max amount of hosts 16777214 172.16.0.0/16 - Used as floating-IP's in skyhigh.hig.no; free in other clouds
Broadcast 172.16.255.255 HostMin 172.16.0.1 HostMax 172.16.255.254 Max amount of hosts 65534 172.17.0.0/16 - Used within NTNU in Gjøvik, and is thus not recommended to use it in openstack networks.
Broadcast 172.17.255.255 HostMin 172.17.0.1 HostMax 172.17.255.254 Max amount of hosts 65534 - 192.168.0.0 - The following twelve subnets are partly used in NTNU Ålesund, the rest are free:
192.168.10.0/24
Broadcast 192.168.10.255
HostMin 192.168.10.1
HostMax 192.168.10.254
Max amount of hosts 254
- 192.168.30.0/24
- 192.168.50.0/24
- 192.168.90.0/24
- 192.168.110.0/24
- 192.168.114.0/24
- 192.168.201.0/24
- 192.168.212.0/24
- 192.168.221.0/24
- 192.168.222.0/24
- 192.168.223.0/24
- 192.168.224.0/24