E2E CloudVPC address ranges
You choose a VPC’s address range when you create it, and the VPC keeps that range for as long as it exists. To use a different range, create a new VPC. Size the range for the resources you expect to have later, as well as the ones you start with.
What a range must look like
Section titled “What a range must look like”A range must be:
- a private IPv4 network, inside 172.16.0.0 to 172.29.255.255 or inside 192.168.0.0/16;
- between /16 and /28 in size;
- written as a network address, with the host bits at zero.
| Value | Accepted |
|---|---|
172.16.231.0/24 |
Yes |
192.168.0.0/16 |
Yes |
172.16.231.5/24 |
No. The host bits must be zero. |
192.168.1.0/16 |
No. The host bits must be zero. |
The Create VPC form lists the ranges you can use under Available ranges and checks yours as you type.
Ranges a VPC refuses
Section titled “Ranges a VPC refuses”A VPC refuses three ranges, even though they are valid private ranges elsewhere: the whole 10.0.0.0/8 block,
including every range inside 10.x.x.x, 172.30.0.0/16, and 172.31.0.0/16.
Everything else inside 172.16.0.0 to 172.29.255.255 and 192.168.0.0/16 is available, so 172.16.231.0/24 and
192.168.50.0/24 are both safe starting points. Two VPCs can use the same range, because each VPC is its own network.
Picking a size
Section titled “Picking a size”| If you expect | Consider |
|---|---|
| A handful of resources, for a test or a demo | /27 or /26 |
| A typical project | /24, with 247 usable addresses, the most common choice |
| A large or growing deployment | /22 or /20 |
| Many resources in one network | /16 |
A /28 leaves only seven usable addresses, which is easy to outgrow. When in doubt, take the larger range, because a range
that is too small means creating a new VPC and moving your resources.
Reserved addresses
Section titled “Reserved addresses”Every VPC sets aside nine addresses from its range for networking: the first eight and the last. In a /24 that starts at .0, those are .0 to .7 and .255. For a VPC on 172.16.231.0/24,
172.16.231.0 to 172.16.231.7 and 172.16.231.255 are reserved, leaving 172.16.231.8 to 172.16.231.254 for your
resources.
The VPC sets these nine aside once for the whole range, so a /16 gives up the same nine addresses that a /28
does.
How many addresses you get
Section titled “How many addresses you get”The Available IPs column in the VPC list shows free addresses over assignable ones. Assignable is every address the VPC can ever hand out: the size of the range, less the nine reserved addresses. Free is how many of those are still unused.
| Size | Addresses in the range | Assignable |
|---|---|---|
/16 |
65,536 | 65,527 |
/20 |
4,096 | 4,087 |
/22 |
1,024 | 1,015 |
/24 |
256 | 247 |
/26 |
64 | 55 |
/27 |
32 | 23 |
/28 |
16 | 7 |
What you can do
Section titled “What you can do”Create a VPC with the range you chose. For help with a message about the range, see Troubleshooting VPC.