Private IPv4 Ranges Summary

Private IPv4 Subnets (RFC1918 Address Space Explained)

Overview
Private IPv4 addresses — defined in RFC 1918 — are used for internal networks that do not require global Internet routing. Every home, business, datacenter, and cloud environment relies heavily on these ranges.

This CSV provides a clean summary of each private block, including:

  • Network address
  • Gateway convention
  • Broadcast address
  • Purpose / usage notes

This allows users to immediately understand how private addressing works and why it’s foundational for NAT, LAN segmentation, VPNs, WiFi networks, cloud VPCs, and enterprise routing.

What This CSV Contains

Each private IPv4 range includes:

  • Subnet (CIDR)
  • Network address
  • Gateway (.1 or first usable)
  • Broadcast address
  • Technical usage note

The three private ranges are:

  • 10.0.0.0/8 — Large enterprise, ISP backbones, massive internal segmentation
  • 172.16.0.0/12 — Corporate VPNs, internal services, medium-sized segmentation
  • 192.168.0.0/16 — Home and SMB LANs, WiFi networks, departmental VLANs

Why This Matters

This table is a great introductory primer for anyone learning:

  • How subnets work
  • Why NAT is required
  • How broadcast domains behave
  • Why certain subnets appear in DHCP pools

It also helps cybersecurity professionals identify when private addresses show up in unusual locations (for example, private ranges leaking across VPN tunnels or misconfigured networks).

Example Subnet (CIDR)Prefix LengthPrivate RangeClassNetwork AddressGateway IP (Example)Broadcast AddressFirst Usable HostLast Usable HostTotal AddressesUsable HostsNotes
10.0.0.0/8810.0.0.0/8A10.0.0.010.0.0.110.255.255.25510.0.0.110.255.255.2541677721616777214Very large private networks; often ISP cores, large enterprises, or big internal address plans (10.0.0.0/8).
172.16.0.0/1212172.16.0.0/12B172.16.0.0172.16.0.1172.31.255.255172.16.0.1172.31.255.25410485761048574Private aggregation for multiple sites or departments (172.16.0.0/12); often split into /16-/24 blocks.
192.168.0.0/1616192.168.0.0/16C192.168.0.0192.168.0.1192.168.255.255192.168.0.1192.168.255.2546553665534Common for large campus or multi-department LANs; often further subnetted into /24s (192.168.0.0/16).
10.0.0.0/202010.0.0.0/8A10.0.0.010.0.0.110.0.15.25510.0.0.110.0.15.25440964094Good for medium-sized segments, shared services, or container/VM clusters (≈4094 usable hosts).
10.0.8.0/212110.0.0.0/8A10.0.8.010.0.8.110.0.15.25510.0.8.110.0.15.25420482046Used for large WiFi pools, guest networks, or dense IoT segments (≈2046 usable hosts).
192.168.0.0/2222192.168.0.0/16C192.168.0.0192.168.0.1192.168.3.255192.168.0.1192.168.3.25410241022Common in data centers or large VLANs where ~1000 hosts are needed (≈1022 usable hosts).
192.168.0.0/2323192.168.0.0/16C192.168.0.0192.168.0.1192.168.1.255192.168.0.1192.168.1.254512510Popular for large access VLANs, WiFi, or combined segments needing ~500 hosts (≈510 usable hosts).
192.168.0.0/2424192.168.0.0/16C192.168.0.0192.168.0.1192.168.0.255192.168.0.1192.168.0.254256254Standard LAN size; typical office, lab, or VLAN network (254 usable hosts).
192.168.0.0/2525192.168.0.0/16C192.168.0.0192.168.0.1192.168.0.127192.168.0.1192.168.0.126128126Smaller secured segments like management, desktops vs. servers, or separated user groups (126 usable hosts).
192.168.0.0/2626192.168.0.0/16C192.168.0.0192.168.0.1192.168.0.63192.168.0.1192.168.0.626462Voice VLANs, cameras, or tightly-scoped access networks (62 usable hosts).
192.168.0.0/2727192.168.0.0/16C192.168.0.0192.168.0.1192.168.0.31192.168.0.1192.168.0.303230Small device groups, labs, or IoT segments (30 usable hosts).
192.168.0.0/2828192.168.0.0/16C192.168.0.0192.168.0.1192.168.0.15192.168.0.1192.168.0.141614Very small segments—testing, out-of-band, or small device clusters (14 usable hosts).
192.168.0.0/2929192.168.0.0/16C192.168.0.0192.168.0.1192.168.0.7192.168.0.1192.168.0.686WAN edges, firewall transit networks, or tiny infrastructure segments (6 usable hosts).
192.168.0.0/3030192.168.0.0/16C192.168.0.0192.168.0.1192.168.0.3192.168.0.1192.168.0.242Classic point-to-point link size (2 usable hosts).
192.168.0.0/3131192.168.0.0/16C192.168.0.0192.168.0.0N/A192.168.0.0192.168.0.122Modern point-to-point links per RFC 3021; both addresses are usable, no broadcast.
192.168.0.10/3232192.168.0.0/16C192.168.0.10192.168.0.10N/A192.168.0.10192.168.0.1011Single host assignment—loopbacks, VIPs, or device-specific addresses.