nsadm.blogg.se - How to find subnet magic number

#How to find subnet magic number how to#
#How to find subnet magic number full#
#How to find subnet magic number plus#

The NEXT subnet (’cause I’m going to work backwards) is 22.19.192.0.

I see 160 is the closest multiple of 32 that is not greater than 178.

The interesting octet is the 3rd octet, so I focus on 178. This one is a bit harder – the interesting octet is the 3rd octet

Next Subnet: 134.27.183.224 (I list this because I actually figure this out then work backwards for the broadcast and last address).

223 (1 less than the next multiple of 8 224-1) 216 – the closest multiple of 8 to 219 that is not greater than 219.

I can see that my subnet number must be.

The “interesting octet” is the last octet, so I focus on 219 So the address you started with is the broacast address for its subnet = 138.43.39.15

The next subnet would be 138.43.39.1 6 ie the NEXT multiple of 16.

Clearly 0 is the only multiple of 16 less than 15.

Your subnet number MUST be less than 15, but one of the multiples of 16 listed above.

Now your “interesting octet” is the 4th octet, which for your IP address is 15. Note that the last entry before 256 is the same as the subnet mask’s “interesting octet”. Told you to learn this didn’t I? By the way, your 32x tables is just every 2nd number from the above., 64x tables every 4th number and 128x tables every 8th number. There you go – that’s your 16x tables up to 256. In your case, where the magic number is 16, the subnet MUST be one of the following: Now read that last section again until it sticks.

The last IP address on any subnet is simply the broadcast address minus 1 in the last octet.

#How to find subnet magic number plus#

The first IP address on any subnet is simply the subnet address plus 1 in the last octet (1,17,33…).ie All of your broadcast addresses will be 1 less than a multiple of 16.The broadcast address on any subnet is simply the next subnet address minus 1 in the last octet.ALL of your subnet numbers will be multiples of 16, starting at 0.The key to understanding subnet is this “magic number”. In your example: Network: 192.168.5.The key concept here is that your subnets will be in groups of size 16Ģ56-240=16. What is the difference between subnet zero and all onessubnet?ģ If a network address is subnetted, the first subnetobtained after subnetting the network address is called subnet zeroand the last subnet obtained is called the all-onessubnet. Example 1- The given picture shows different floors in a building. Ordinal numbers tell the position of an object rather than their quantity. The numbers which give us the exact position of an object are called ordinal numbers. By adding the magic number to the interesting octet of subnet number and subtract 1. The left part should be filled already in Find subnet number, the upper.

#How to find subnet magic number how to#

How to find the interesting octet of a subnet?įor any octets fully to the right of the interesting column, put 255s in the broadcast address. For any octets fully to the right of the interesting column, put 255s in the broadcast address. How do you find the broadcast address of a subnet?įind the broadcast address. 0.0 is a valid subnet mask as opposed to 255.0. A subnet mask, like an IP address, is made up of four numbers. 255.0, this means that whatever ip address the device has also belongs to a network with potentially 253 other device addresses.Ī subnet mask distinguishes the network identifier from the host identifier in an IP address, but is not restricted by the same rules as the class-based method. The subnet is just the allocation of the IP addresses. What does the subnet mask 255.255 255.0 tell a router? Subnet Cheat Sheet – 24 Subnet Mask, 30, 26, 27, 29, and other IP Address CIDR Network References CIDR 24 indicates that the first 24 bits of the address are masked (255.255.255.0). Hello Allan49, the /24 is referring to the subnet mask.

#How to find subnet magic number full#

The subnet number helps browsers to accurately use the Internet to deliver messages to specific parts of a party’s full network. A subnet number is a specific part of a subnet address in an IP address that identifies one among several subnets as the recipient or originator of a data packet.