IP and addressing
Subnets, CIDR, IPv6, NAT and MAC addresses.
Tools 7
Learn 24
- Subnet Cheat Sheet (CIDR, Masks, Host Counts)
- What Is a MAC Address?
- What Is a Subnet? Subnetting Explained
- What Is an IP Address?
- CIDR Notation Explained
- DNS vs DHCP
- IPv4 vs IPv6: What's the Difference?
- LAN vs WAN
- Public vs Private IP Address
- Static vs Dynamic IP Address
- Unicast vs Multicast vs Broadcast
- What Is a Default Gateway?
- What Is a Link-Local Address?
- What Is a Loopback Address?
- What Is a Subnet Mask?
- What Is an ASN (Autonomous System Number)?
- What Is Anycast?
- What Is ARP?
- What Is BGP?
- What Is CGNAT?
- What Is DHCP?
- What Is Dynamic DNS?
- What Is IPv6?
- What Is NAT?
Tutorials 6
Fixes 5
Library 39
- 0.0.0.0: What It Means
- 1.1.1.1: Cloudflare's DNS Resolver
- 10.0.0.1: Router Login (Xfinity and Others)
- 127.0.0.1: The Loopback Address
- 192.168.0.1: Router Login and Admin Page
- 192.168.1.1: Router Login and Admin Page
- 192.168.1.254: Router Login (AT&T and Others)
- 255.255.255.255: The Broadcast Address
- 8.8.8.8: Google Public DNS
- AT&T DNS Servers, CGNAT and IPv6
- Comcast Xfinity DNS Servers, CGNAT and IPv6
- Spectrum DNS Servers, CGNAT and IPv6
- Starlink CGNAT, DNS and IPv6
- Verizon DNS Servers, CGNAT and IPv6
- /10 Subnet: 255.192.0.0, 4,194,302 Usable Hosts
- /11 Subnet: 255.224.0.0, 2,097,150 Usable Hosts
- /12 Subnet: 255.240.0.0, 1,048,574 Usable Hosts
- /13 Subnet: 255.248.0.0, 524,286 Usable Hosts
- /14 Subnet: 255.252.0.0, 262,142 Usable Hosts
- /15 Subnet: 255.254.0.0, 131,070 Usable Hosts
- /16 Subnet: 255.255.0.0, 65,534 Usable Hosts
- /17 Subnet: 255.255.128.0, 32,766 Usable Hosts
- /18 Subnet: 255.255.192.0, 16,382 Usable Hosts
- /19 Subnet: 255.255.224.0, 8,190 Usable Hosts
- /20 Subnet: 255.255.240.0, 4,094 Usable Hosts
- /21 Subnet: 255.255.248.0, 2,046 Usable Hosts
- /22 Subnet: 255.255.252.0, 1,022 Usable Hosts
- /23 Subnet: 255.255.254.0, 510 Usable Hosts
- /24 Subnet: 255.255.255.0, 254 Usable Hosts
- /25 Subnet: 255.255.255.128, 126 Usable Hosts
- /26 Subnet: 255.255.255.192, 62 Usable Hosts
- /27 Subnet: 255.255.255.224, 30 Usable Hosts
- /28 Subnet: 255.255.255.240, 14 Usable Hosts
- /29 Subnet: 255.255.255.248, 6 Usable Hosts
- /30 Subnet: 255.255.255.252, 2 Usable Hosts
- /31 Subnet: 255.255.255.254, 2 Usable Hosts
- /32 Subnet: 255.255.255.255, 1 Usable Host
- /8 Subnet: 255.0.0.0, 16,777,214 Usable Hosts
- /9 Subnet: 255.128.0.0, 8,388,606 Usable Hosts