/27 vs /29 — Subnet Comparison
A /27 subnet is 4× larger than a /29. Every additional bit in the prefix halves the address space — the 2-bit difference between these two means /27 has 22 = 4 times as many addresses.
30 usable hosts — small workgroup
Typical Uses
- →Small workgroup LAN
- →Network device management subnet
- →Cloud NAT gateway subnet
6 usable hosts — tiny cluster
Typical Uses
- →Small server cluster (web + app + db)
- →Infrastructure management segment
- →Very small office or branch
Key Differences
How 4 /29 Subnets Divide a /27
Example using 10.0.0.0/27 as the parent block.
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.0.0.0/29 | 10.0.0.0 | 10.0.0.1 | 10.0.0.6 | 10.0.0.7 | 6 |
| 2 | 10.0.0.8/29 | 10.0.0.8 | 10.0.0.9 | 10.0.0.14 | 10.0.0.15 | 6 |
| 3 | 10.0.0.16/29 | 10.0.0.16 | 10.0.0.17 | 10.0.0.22 | 10.0.0.23 | 6 |
| 4 | 10.0.0.24/29 | 10.0.0.24 | 10.0.0.25 | 10.0.0.30 | 10.0.0.31 | 6 |
FAQ
What is the difference between /27 and /29?
A /27 has 30 usable hosts
and a /29 has 6.
The subnet masks differ: /27 uses 255.255.255.224
while /29 uses 255.255.255.248.
Every additional bit in the prefix halves the number of addresses — so the 2-bit gap means
/27 is exactly 4× larger.
How many /29 subnets fit in a /27?
Exactly 4 /29 subnets fit perfectly inside one /27 with no wasted space. To split a /27 into /29s, just increment the last 2 bits of the network address for each new subnet.
Which should I choose?
/27 is typically used for: Small workgroup / management subnet. /29 is better for: Tiny server cluster or infra segment. Choose the smallest prefix that comfortably fits your host count — over-allocating wastes address space, but under-allocating means painful renumbering later.