Subnet mask value defines properties of IP Address to which it can communicate and to which it can not Subnet mask value defines Network component and host component of an IP address Ip address uses subnet mask to find out boundaries of network Subnet mask value is a driver of IP address Network Bits are always represented with !ost bits are always represented with "
Subnet Mask Structure: #lass A Subnet Mast structure N$!$!$! $""""""""$""""""""$"""""""" %&&$"$"$" #lass B Subnet Mask Structure N$N$!$! $$""""""""$""""""""
Network Address is the identification address for all the systems in the network (he systems with same network address can communicate with each other Systems with different network addresses can not communicate )enerally
'hat is Broadcast Address •
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Broadcast Address is used to deliver a broadcast messa)e to all the computers in the network (he systems with same network address can have same broadcast address All the systems in between Network address and broadcast address form a lo)ical network to communicate with each other$
note:Network Address and Broad cast Address are the boundaries of a network$ (hey can*t be assi)ned to computers !ow to find out Network Address •
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Identify class of IP address and Subnet mask Structure$ +eplace host portion with *"*,orPerform a lo)ical AN. operation between IP Address and subnet mask value
!ow to find out Broadcast Address •
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Identify class of Ip Address and Subnet mask Structure +eplace !ost portion with %&& perform a lo)ical /+ operation between IP Address and inverse Subnetmask value
IP address +elated /r)ani9ations: IANAinternet Assi)ned Numbers Authority I#ANNInternet #orporation for Assi)ned Numbers and names Private IP Address: • • • •
(he IP addresses not routable in public network ;sed to communicate within private network Internet access is not possible with private ip address .efined in +<# 42
Network is reserved for default routin)$ #annot assi)ned to systems %6$"$"$" Network is reserved for loop back purpose ,NI# dia)nosis#lass . Networks are reserved for multicastin)$ Not for systems #lass 0 Networks are reserved for +esearch and .evelopment$ Not for systems
Subnettin)
'hat is subnettin)= >o)ically breakin) the ma?or network into smaller networkssubnets Advanta)e of subnettin) +educe wasta)e of ip address Subnettin) Procedure: Increase network bits in the subnet mask value from left to ri)ht Subnettin) formulae: No$ of networks 5 %pwer n N5increased network bits No$ of !osts per network 5,% power !-% !5remainin) host bits Subnettin) Methods: Subnettin) can be done in two ways
Based on No$of Networks Based on No$ of !osts
Subnettin) #alculations: Based on No$ of Networks: Identify re@uired No$ of subnets +efer % power chart Identify N value Increast the bits in the subnetmask value Identify ! value
Based on No$ of hosts: o o o o o o o o o
Identify re@uired No$ of hosts per subnet +efer % power hart Identify ! value Increase the bits in the subnetmask value Identify N value
01ercise: .ivide 4%$82$""$" into 7 subnets .ivide "$"$"$" into " subnets .ivide 6%$8$"$"$ into 8 subnets .ivide 4%$82$""$" into subnets with %2 hosts .ivide "$"$"$" into subnets with 7""" hosts .ivide 6%$8$"$" into subnets &"" hosts
V>SM
'hat is vlsm
Variable length subnet Mask Also called as subnetting of subnetting Subnetting is used to break the network equally If these networks are subneetted again, different subnets may have different subnet mask values, also called as Variable length subnet masks With vlsm, IP addressing scheme is used more efficiently without wastage Subnetting and VSM com!arisions • • • •
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Subnetting "reaking netwok equally Sub#netting $as same subnet mask value %educe IP wastage
VSM "reaking network unequally Subnetting of subnetting $as different subnet mask values %educe IP wastage more effectively
&esign IP address scheme for the network with '()*'+*'*"ranch' "ranch ) "ranch . "ranch'#) wan link "ranch )#. wan link "ranch .#' wan link
