CIDR Notation / Network Prefix

-

 Classless Inter-Domain Routing -CIDR

=========================================================================
SID = Subnet ID, HID = Host ID, NID = Network ID


===============================================================

There is a simple scenario of CIDR,

192.240.10.0/28


1) Network id bit ?

     This is class C ip. So network id have first 3 octet in ip. It is 24 bits. NID = 24 bits

2) Subnet id bit ?

     CIDR = 28  = NID + SID = 24 +4 

     Then SID = 4 bits

3) Subnets ?

     We can find the subnet count by SID count 

     SID = 4 bits, So 2^4 = 16

     So there are 16 subnets

4) Host id bit ?

     All ip bits - (NID + SID)

    32-28 = 4

    4 hosts

5) Address count ?

    This depend on host id bits count,

    HID = 4, So 2^4 = 16

6) Host count ?

    NA = Network Address, BA = Broadcast Address

    All IP host bit Count - (NA +BA)

    16 -2 = 14

7) Subnet Mask ?

    we can find the subnet mask by adding value 1 for NID, SID and adding value 0 for HID.

    CIDR = NID + SID

    So that similar to find the subnet mask by adding value 1 CIDR and adding value 0 for            HID.

    Then,

    11111111.11111111.11111111.11110000

            255            255          255         240

    Subnet mask = 255.255.255.240



 

Comments

Post a Comment

Popular posts from this blog

Seedr - The fastest way to download Torrents

-
Image
  Hi guys. Today, I am going to talk about a special website. Its name is seedr. For entertainment, we are using it to download lot of torrent files like movies, tv-series, games, etc. But there are have some issues. When we download a torrent, its download speed depends on the seeders and leechers. sometimes we have to wait for hours. But if you are trying to use the seedr website, you don't have to wait for a long times for downloads. This website is downloading our files super-fast. So that's awesome. You can paste the magnet link in the top of the text box in the seedr website and click the plus button. After a little time, your file is ready to download. The registration is also very easy. After the registration, you will get free 2 GB capacity to download unlimited times. You can freely increase some capacity doing some little activities. Those are mentioned in the seedr website. By the way, if you want more capacity, for some reason you can choose a subscription option a
Read more

Subnet ID

-
Image
If any requirement to subnet some network, we must need the subnet id. Subnet id use for identity which subnet in the network. we get an example scenario here. There is an ABC company. That company have 4 divisions.  So that network wants 4 subnets. but how to apply subnets to the computer. It`s also doing by bits. 1 bit have 0 and 1. So there are two IDs . In this scenario, we want 4 subnets. Then we want 4 IDs. since we need 2 bits  1 bit =0, 1 2 bit = 00, 01, 10, 11 how to include subnet id into the IP address. if we get a class c address as 192.168.10.4, this IP network id can not change, only the host id can change. So we book some bits for subnet id from that host id. Subnet      Subnet ID   (2 bit) D1             00 D2             01 D3             11 D4             10 D1 (00) 192.168.10.00 000000  (192.168.10.0) Network Address 192.168.10.00 000001  (192.168.10.1) 192.168.10.00 000010  (192.168.10.2)                  | 192.168.10.00 111111   (192.168.10.63) Broadcast Address  
Read more