{"id":325,"date":"2017-02-03T07:53:00","date_gmt":"2017-02-03T07:53:00","guid":{"rendered":"https:\/\/opstree.com\/blog\/\/2017\/02\/03\/classless-inter-domain-routing-made-easy-cont\/"},"modified":"2019-09-18T13:29:11","modified_gmt":"2019-09-18T07:59:11","slug":"classless-inter-domain-routing-made-easy-cont","status":"publish","type":"post","link":"https:\/\/opstree.com\/blog\/2017\/02\/03\/classless-inter-domain-routing-made-easy-cont\/","title":{"rendered":"Classless Inter Domain Routing Made Easy (Cont..)"},"content":{"rendered":"
\n

Introduction :<\/b><\/h2>\n
As we had a discussion  about Ip addresses and their classes in the previous blog,<\/b><\/b>we can now start with Sub-netting<\/b>.
<\/span><\/b><\/div>\n

Network Mask \/Subnet Mask –<\/b><\/h2>\n
As mask means to cover something,<\/div>\n
IP Address is made up of two components, One is the network address and the other is the host address.The Ip Address needs to be separated into the network and host address, and this separation of network and host address in done by Subnet Mask.The host part of an IP Address is further divided into subnet and host address if more subnetworks are needed and this can be done by subnetting. It is called as a subnet mask or Network mask as it is used to identify network address of an IP address by performing a bitwise AND operation on the netmask.<\/div>\n
Subnet Mask is of 32 Bit and is used to divide the network address and host addresses of an IP.<\/div>\n
In a Subnet Mask all the network bits are set to 1\u2019s and all the host bits are set to 0\u2019s.<\/div>\n
 <\/div>\n
Whenever we see an IP Address – We can easily Identify that<\/div>\n
WHAT IS NETWORK PART OF THAT IP<\/div>\n
WHAT IS THE HOST PART OF THAT IP<\/div>\n
 <\/div>\n
FORMAT :<\/strong><\/div>\n
mmmmmmmm.mmmmmmmm.mmmmmmmm.mmmmmmmm<\/div>\n
(Either it will have 1 or 0 Continuously)<\/strong><\/div>\n
EXAMPLE :<\/strong><\/span><\/div>\n
A Class Network Mask<\/strong><\/div>\n
In Binary : 11111111.00000000.00000000.00000000         – First 8 Bits will be Fixed
In Decimal : 255.0.0.0<\/div>\n
Let the IP Given is – 10.10.10.10<\/div>\n
When we try to Identify it we know that it belong to class A, So the subnet mask will be : 255.0.0.0<\/div>\n
And the Network Address will be : 10.0.0.0<\/div>\n
 <\/div>\n
B Class Network Mask  <\/strong><\/div>\n
In Binary : 11111111.11111111.00000000.00000000           – First 16 Bits will be Fixed<\/div>\n
In Decimal : 255.255.0.0<\/div>\n
Let the IP Given is -150.150.150.150<\/div>\n
When we try to Identify it we know that it belong to class B, So the subnet mask will be : 255.255.0.0<\/div>\n
And the Network Address will be : 150.150.0.0<\/div>\n
 <\/div>\n
C Class Network Mask<\/strong>  <\/div>\n
In Binary : 11111111.111111111.11111111.00000000           – First 32 Bits will be Fixed<\/div>\n
In Decimal : 255.255.255.0<\/div>\n
Let the IP Given is – 200.10.10.10<\/div>\n
When we try to Identify it we know that it belong to class C, So the subnet mask will be : 255.255.255.0<\/div>\n
And the Network Address will be : 200.10.10.0<\/div>\n

Subnetting :<\/b><\/h2>\n
The method of dividing a network into two or more networks is called subnetting.<\/div>\n
A subnetwork, or subnet, is a logically subdivision of an IP network<\/div>\n
Subnetting provides Better Security<\/div>\n
Smaller collision and Broadcast  Domains<\/div>\n
Greater administrative control of each network.<\/div>\n
Subnetting – WHY ??<\/strong><\/div>\n
Answer : Shortage of IP Addresses<\/strong><\/div>\n
SOLUTIONS : –<\/strong><\/div>\n
1) SUBNETTING<\/strong> – To divide Bigger network into the smaller networks and to reduce the wastage<\/div>\n
2) NAT –<\/strong>  Network Address Translation<\/div>\n
3) Classless IP Addressing –<\/strong><\/div>\n
No Bits are reserved for Network and Host<\/div>\n
 <\/div>\n
**Now the Problem that came is how to Identify the Class of IP Address :**<\/strong><\/div>\n
Let a IP Be : 10.10.10.10<\/strong><\/div>\n
If we talk about classful we can say it is of class A But in classless : We can check it through subnetwork mask.<\/div>\n
255.255.255.0<\/strong><\/div>\n
So by this we can say that first 24 bits are masked for network and the left 8 are for host.<\/div>\n
Bits Borrowed from Host and added to Network<\/strong><\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
Network ID(N)<\/div>\n<\/td>\n
\n
Network ID(N)<\/div>\n<\/td>\n
\n
Host ID(H)<\/div>\n<\/td>\n
\n
Host ID(H)<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
Network ID(N)<\/div>\n<\/td>\n
\n
Network ID(N)<\/div>\n<\/td>\n
\n
Subnet<\/div>\n<\/td>\n
\n
Host ID(H)<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
Network ID(N)<\/div>\n<\/td>\n
\n
Network ID(N)<\/div>\n<\/td>\n
\n
Subnet<\/div>\n<\/td>\n
\n
Subnet\/Host<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Let we have a<\/strong><\/div>\n
150.150.0.0 – Class Identifier\/Network Address<\/strong><\/div>\n
150.150.2.4 – Host Address<\/strong> – IP GIVEN TO A HOST<\/div>\n
255.255.255.0 – Subnet Mask<\/strong><\/div>\n
150.150.2.0 – Subnet Address<\/strong><\/div>\n

CIDR : Classless Inter Domain Routing<\/h3>\n
CIDR (Classless Inter-Domain Routing, sometimes called supernetting) is a way to allow more flexible allocation of Internet Protocol addresses than was possible with the original system of IP Address classes. As a result, the number of available Internet addresses was greatly increased, which along with widespread use of network address translation, has significantly extended the useful life of IPv4.<\/div>\n
Let a IP be – 200.200.200.200<\/div>\n
 <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
Network ID(N)<\/div>\n<\/td>\n
\n
Host ID(H)<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
——–24 Bit ——– ——-8 bit ———–
   <\/div>\n
Network Mask<\/strong> tells that the number of 1\u2019s are Masked<\/div>\n
Here First 24 Bits are Masked<\/div>\n
In Decimal : 255.255.255.0<\/div>\n
In Binary : 11111111.11111111.11111111.00000000<\/div>\n
   Here the total Number of 1\u2019s : 24<\/div>\n
So we can say that 24 Bits are masked.<\/div>\n
 <\/div>\n
This method of Writing the network mask can be represented in one more way<\/div>\n
And that representation is called as CIDR METHOD\/CIDR NOTATION<\/div>\n

CIDR  – 200.200.200.200\/24<\/strong><\/div>\n
24 : Is the Number of Ones – Or we can say Bits Masked<\/div>\n
Basically the method ISP\u2019s(Internet Service Provider)use to  allocate an amount of addresses to a company, a home<\/div>\n
 <\/div>\n
EX :<\/strong><\/div>\n
190.10.20.30\/28 : Here 28 Bits are Masked that represents the Network and the remaining 4 bits represent the Host<\/div>\n
\/ – Represents how many bits are turned on (1s)<\/div>\n

CLASS C SUBNETTING :<\/h4>\n
 <\/div>\n
Determining Available Host Address :<\/strong><\/div>\n
 <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
11001000               00001010               00010100                 00000000 – 1<\/div>\n
                                                                                              00000001 – 2     <\/div>\n
                                      00000011 – 3<\/div>\n
                                                                          .<\/div>\n
                                                                                                    .<\/div>\n
                                                                                                    .<\/div>\n
                                                                                              11111101 – 254<\/div>\n
                                                                                              11111110 – 255<\/div>\n
                                                                                              11111111 – 256     <\/div>\n
                                                                                                                    -2<\/div>\n
                                                        <\/span>                                                       ———<\/div>\n
                                                                                                                   254<\/div>\n
    2^N – 2  = 2^8 -2 = 254<\/div>\n
           (Coz we have 8 bits in this case)               – 2 (Because 2 Address are Reserved)<\/div>\n
254 Address are available here<\/div>\n
 <\/div>\n
FORMULAS :<\/strong><\/div>\n
 <\/div>\n
Number of Subnets : ( 2^x ) – 2<\/strong>     (x : Number of Bits Borrowed)<\/div>\n
Number of Hosts : ( 2^y ) – 2   <\/strong>      (y : Number of Zero\u2019s)<\/div>\n
Magic Number or Block Size = Total Number of Address<\/strong> : 256 – Mask<\/div>\n
Let a IP ADDRESS BE 200.10.20.20\/24<\/strong><\/div>\n
Number of subnets : 5<\/strong><\/div>\n
 <\/div>\n
Network Address   :<\/strong><\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
255<\/div>\n<\/td>\n
\n
255<\/div>\n<\/td>\n
\n
255<\/div>\n<\/td>\n
\n
0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
(as total Number of 1\u2019s : 24)<\/strong><\/div>\n
IP in Binary<\/strong><\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
11001000<\/div>\n<\/td>\n
\n
00001010<\/div>\n<\/td>\n
\n
00010100<\/div>\n<\/td>\n
\n
00010100<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
MASK<\/strong><\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
11111111<\/div>\n<\/td>\n
\n
11111111<\/div>\n<\/td>\n
\n
11111111<\/div>\n<\/td>\n
\n
00000000<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n
And Operation in IP And Mask<\/strong><\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
11001000<\/div>\n<\/td>\n
\n
00001010<\/div>\n<\/td>\n
\n
00010100<\/div>\n<\/td>\n
\n
00000000<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
In Binary<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
As we need 5 Subnets :<\/div>\n
2^n -2 => 5<\/div>\n
So the value of n = 3 that satisfies the condition<\/div>\n
So, We need to turn 3 Zero\u2019s to One\u2019s to create 5 subnets<\/div>\n
 <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
11001000<\/div>\n<\/td>\n
\n
00001010<\/div>\n<\/td>\n
\n
00010100<\/div>\n<\/td>\n
\n
00000000<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
 <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
11001000<\/div>\n<\/td>\n
\n
00001010<\/div>\n<\/td>\n
\n
00010100<\/div>\n<\/td>\n
\n
11100000<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
 (3 Zero\u2019s changed to 3 one\u2019s)    <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
224<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
                                                                                  <\/div>\n
Subnet 0   <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
0\/27  <\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 1                                           +32 – Block Size<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
32\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 2                                            +32<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
64\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 3<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
96\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 4<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
128\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 5   <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
160\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 6<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
192\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 7<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
224\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n
How to Put Host ADD.<\/div>\n
Subnet 0   <\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
0\/27  <\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet Broadcast Number 0<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
31 \/27  <\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet 1                                           +32 – Block Size<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
31\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
32\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
33\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
                                                          .<\/div>\n
                                                          .<\/div>\n
                                                          .<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
62\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Subnet Broadcast Subnet 1<\/div>\n
\n\n\n\n\n\n<\/colgroup>\n\n\n
\n
200<\/div>\n<\/td>\n
\n
10<\/div>\n<\/td>\n
\n
20<\/div>\n<\/td>\n
\n
63\/27<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
200.10.20.33 \u2026.and so on till 200.10.20.62   – 13 Host can be assigned IP Address.<\/div>\n

Conclusion :<\/h1>\n
As the world is growing rapidly towards digitalization, use of IP Addresses is also increasing, So to decrease the wastage of IP Addresses, the implementation of CIDR is important that allows more organizations and users to take advantage of IPV4.<\/div>\n<\/div>\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

Introduction : As we had a discussion  about Ip addresses and their classes in the previous blog,we can now start with Sub-netting. Network Mask \/Subnet Mask – As mask means to cover something, IP Address is made up of two components, One is the network address and the other is the host address.The Ip Address … Continue reading “Classless Inter Domain Routing Made Easy (Cont..)”<\/span><\/a><\/p>\n","protected":false},"author":171775670,"featured_media":29900,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false},"version":2}},"categories":[28070474],"tags":[4496498,676319256,676319257,768739308,676319247,768739285,7156914,4721238,374492],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/opstree.com\/blog\/wp-content\/uploads\/2025\/11\/DevSecOps-1.jpg","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/pfDBOm-5f","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/posts\/325"}],"collection":[{"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/users\/171775670"}],"replies":[{"embeddable":true,"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/comments?post=325"}],"version-history":[{"count":3,"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/posts\/325\/revisions"}],"predecessor-version":[{"id":1098,"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/posts\/325\/revisions\/1098"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/media\/29900"}],"wp:attachment":[{"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/media?parent=325"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/categories?post=325"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/opstree.com\/blog\/wp-json\/wp\/v2\/tags?post=325"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}