How many usable hosts does a /29 subnet have?

A /29 subnet has 6 usable host addresses out of 8 total IPs. Two addresses are reserved: the network address (x.x.x.0 on an 8-boundary) and the broadcast address (x.x.x.7). In AWS, only 3 IPs are usable because AWS reserves 5 IPs per subnet.

Is a /29 subnet big enough for AWS?

A /29 subnet leaves only 3 usable IPs in AWS after the 5 reserved addresses (.0 network, .1 VPC router, .2 DNS, .3 future use, .7 broadcast). This is rarely sufficient for any real workload. AWS recommends using /28 (11 usable) or larger for practical deployments.

What is the subnet mask for a /29?

The subnet mask for a /29 network is 255.255.255.248. In binary, 29 bits are set to 1 followed by 3 bits of 0: 11111111.11111111.11111111.11111000.

What is a /29 Subnet?

Last reviewed: May 2026

A /29 subnet contains 8 total IP addresses and 6 usable host addresses. The "/29" prefix means 29 bits are used for the network portion, leaving 3 bits (2³ = 8) for host addressing. The /29 is one of the smallest practical subnet sizes, commonly used for tightly scoped server clusters and management segments.

Calculate any /29 subnet instantly →

Quick Facts: /29 Subnet Subnet mask: 255.255.255.248 · Wildcard: 0.0.0.7 · Network: x.x.x.0 (on 8-boundary) · Broadcast: x.x.x.7 · Total IPs: 8 · Usable hosts: 6

Full Breakdown

Property	Value
Prefix length	/29
Subnet mask	255.255.255.248
Wildcard mask	0.0.0.7
Total addresses	8
Usable host addresses	6
Network address	x.x.x.0 (must align to multiples of 8: .0, .8, .16, .24, …)
Broadcast address	x.x.x.7 (last address in the block)
Binary mask	11111111.11111111.11111111.11111000
AWS usable hosts	3 (AWS reserves 5 IPs per subnet)

AWS Warning: /29 Leaves Only 3 Usable IPs

In AWS, a /29 leaves only 3 usable IPs after the 5 reserved addresses (.0 network, .1 VPC router, .2 DNS, .3 future use, .7 broadcast). For any real workload, use /28 or larger. The /28 gives 11 usable IPs and is the AWS-recommended minimum for most use cases.

Common Use Cases for /29 Subnets

Small server clusters — a web server, app server, and database server fit comfortably in a /29 with room to spare
Management VLANs — out-of-band management for up to 6 switches, routers, or servers in a small rack
IoT device segments — dedicated subnets for small clusters of IoT sensors, cameras, or environmental monitors
Small branch office networks — suitable for offices where fewer than 6 devices share a segment
Point-to-multipoint links — where a small number of endpoints need IP addresses beyond a /30

Comparison: /29 vs Nearby Prefix Lengths

CIDR	Subnet Mask	Total IPs	Usable Hosts	AWS Usable	Typical Use
/27	255.255.255.224	32	30	27	Azure GatewaySubnet, infrastructure
/28	255.255.255.240	16	14	11	AWS minimum; small managed subnet
/29	255.255.255.248	8	6	3	Small server cluster; management VLAN
/30	255.255.255.252	4	2	—	Point-to-point links (not usable in AWS)

How Many /29 Subnets Fit in a /24?

A /24 block contains 2^(29−24) = 32 subnets of /29 size. For example, 192.168.1.0/24 can be subdivided into 192.168.1.0/29, 192.168.1.8/29, 192.168.1.16/29, … 192.168.1.248/29. Each block starts on a multiple of 8.

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