10.0.0.0/24 — the top slice of 10/8
10.0.0.0/24 is the very first /24 carved out of the 10.0.0.0/8 private block: 256 addresses, 10.0.0.0 through 10.0.0.255. It punches far above its weight in search traffic for one reason — Comcast and Xfinity gateways default to 10.0.0.1, so millions of households quietly live on this subnet.
In corporate networks it plays a different role: the "first subnet" of the big private block, often the original LAN from which the rest of a 10.x design grew.
| Network address | 10.0.0.0 |
| Subnet mask | 255.255.255.0 |
| Wildcard mask | 0.0.0.255 |
| Broadcast address | 10.0.0.255 |
| First usable | 10.0.0.1 |
| Last usable | 10.0.0.254 |
| Total addresses | 256 |
| Usable hosts | 254 |
10.0.0.1 and the Xfinity effect
If you have a Comcast XB-series gateway, browsing to 10.0.0.1 opens its admin panel. The choice is deliberate: cable ISPs moved their CPEs to 10.x to stop colliding with customers' own routers, which overwhelmingly use 192.168.x. It is the same collision-avoidance logic enterprises apply, executed at national scale.
A /24 versus the whole /8
Do not confuse the slice with the pie. Assigning 10.0.0.0/8 to a single LAN — a real thing lazy configs do — wastes 16.7 million addresses and makes later segmentation painful. Sizing the LAN as 10.0.0.0/24, or whatever /20 to /24 fits the device count, keeps the rest of 10/8 free for future sites, VPN pools and Kubernetes clusters.
CIDR Calculator
Run the math on 10.0.0.0/24 — or any other block
Frequently asked questions
What is 10.0.0.1?
A private gateway address — most famously the default LAN IP of Comcast/Xfinity routers, where their admin interface lives. It is also a common choice for the firewall at the top of a corporate 10.x network.
How many hosts are in 10.0.0.0/24?
254 usable addresses: 256 total, minus the network address 10.0.0.0 and the broadcast address 10.0.0.255.
Is 10.0.0.0/24 the same as 10.0.0.0/8?
No. The /24 is one 256-address subnet at the very start of the range; the /8 is the entire 16.7-million-address private block. One is a LAN, the other is the whole reservation.