The /29 subnet, explained
Everything about a /29 CIDR block — mask, address count, usable hosts and where a /29 fits in real network plans.
| Prefix length | /29 — 29 network bits, 3 host bits |
| Subnet mask | 255.255.255.248 |
| Wildcard (ACL) mask | 0.0.0.7 |
| Binary mask | 11111111.11111111.11111111.11111000 |
| Total addresses | 2^3 = 8 |
| Usable hosts | 6 (total − network − broadcast) |
| A /16 holds | 8,192 × /29 subnets |
| Example block | 192.168.1.0/29 |
Notes
A /29 prefix means the first 29 bits of the 32-bit IPv4 address identify the network and the remaining 3 bits identify hosts — giving 2^3 = 8 addresses. The first address (network) and the last (broadcast) are not assignable in a standard subnet.
Cloud sizing: too small for an AWS VPC (minimum /28 per VPC, /29 allowed for GCP subnets).
Adjacent sizes: /8 · /9 · /10 · /11 · /12 · /13 · /14 · /15 · /16 · /17 · /18 · /19 · /20 · /21 · /22 · /23 · /24 · /25 · /26 · /27 · /28 · /30 · /31 · /32
Frequently asked questions
How many IP addresses are in a /29?
8 total addresses, of which 6 are usable hosts (network and broadcast addresses are reserved).
What is the subnet mask for /29?
255.255.255.248 (wildcard mask 0.0.0.7).
What does /29 mean in an IP address?
The /29 suffix is CIDR notation: the first 29 bits are the network part, the last 3 bits are the host part.