Tagged with subnet mask

Subnet Mask Reference Table

Subnet size (# of hosts) Subnet Mask First host in block 2 hosts 255.255.255.252 1,5,9,13,17,21,25,…. 3 – 6 255.255.255.248 1,9,17,25,33,… 7 – 15 255.255.255.240 1,17,33,49,65,… 16 – 31 255.255.255.224 1,33,65,97,129,… 32 – 63 255.255.255.192 1,65,129,193,… 64 – 127 255.255.255.128 1 & 129 128 – 255 255.255.255.0 1 256 – 511 255.255.254.0 1,5,9,13,17,21,25,…. 512 – 1023 … Continue reading

Subnetting Notes

Boolean Logic 0 AND 0 = 0 0 AND 1 = 0 1 AND 0 = 0 1 AND 1 = 1 0 OR 0 = 0 0 OR 1 = 1 1 OR 0 = 1 1 OR 1 = 1 Useful Graph This graph helps me reduce the number of errors I make … Continue reading

Understanding the /24 after the IP

Sometimes people can find an IP written like 192.168.0.1/24 and they wonder about what that means, here’s a good explanation: IP addresses are written in decimal notation but are best understood in binary. Decimal is what we count in and goes from 0 to 9 – hex foes from 0 to 1 (0,1) giving 2 … Continue reading