/9 Subnet
Subnet Mask
255.128.0.0
Wildcard Mask
0.127.255.255
Total IPs
8,388,608
Usable Hosts
8,388,606
Network Bits
9
Host Bits
23
About /9 Networks
Large ISP or enterprise allocation. A /9 subnet uses the mask 255.128.0.0 and provides 8,388,606 usable host addresses out of 8,388,608 total IPs.
Example /9 Networks
| Network | Broadcast | First Host | Last Host |
|---|---|---|---|
| 10.0.0.0/9 | 10.127.255.255 | 10.0.0.1 | 10.127.255.254 |
| 172.0.0.0/9 | 172.127.255.255 | 172.0.0.1 | 172.127.255.254 |
| 192.128.0.0/9 | 192.255.255.255 | 192.128.0.1 | 192.255.255.254 |
| 192.128.0.0/9 | 192.255.255.255 | 192.128.0.1 | 192.255.255.254 |
| 8.0.0.0/9 | 8.127.255.255 | 8.0.0.1 | 8.127.255.254 |
Adjacent CIDRs
Frequently Asked Questions
What is a /9 subnet?
A /9 subnet uses the subnet mask 255.128.0.0 with 8,388,606 usable host addresses and 8,388,608 total IP addresses. It has 9 network bits and 23 host bits.
How many hosts in a /9 network?
A /9 network supports 8,388,606 usable hosts out of 8,388,608 total IP addresses. The usable range excludes the network address and broadcast address.
What subnet mask does /9 use?
A /9 subnet uses the mask 255.128.0.0 (wildcard mask 0.127.255.255). This means the first 9 bits identify the network and the remaining 23 bits identify hosts.