1. Internet and IP infrastructure

2. IPv4 addressing
IP address has two parts – network address and host address
Classful IP addressing – addressing to the boundary of 8- bits
Classless Interdomain Routing (CIDR) – address are assigned as per ISPs and hosts instead of 8-bit octets
Class A – 126 networks with 16,777,214 hosts
Class B – networks with 65,534 hosts
Class C – 2,097,152 networks with 254 hosts
Class D – reserves for multicast
Class E – reserved for experimental purposes

3. IPv4 addressing Digits in IP address tells a number of things
124 – Class A (Net ID)
– Host ID
– Class B (Net ID)
88.7 – Host ID
Net ID’s are managed by RIR (APNIC, ARIN, RIPE, NCC, LACNIC, AfriNIC)
IPv4 makes available almost 4.3 billion addresses (232)

4. CIDR Eliminates the old 8-bit octet style
Large networks can be broken down into subnetworks or combined into supernetworks
An IP address is a combination of an address and a mask (e.g., /23)
Mask – no. of bits used for network prefix ( )
CIDR supporting protocols are RIPv2, OSPFv2, EIGRP, BGP4

5. NAT
NAT (Network Address Translator) is a technique to overcome shortage of IP addresses
It allows LAN to use one set of IP address for internal traffic (i.e., Private IP) and another set for external traffic
Private IP – /8, /12, /16
The translation from internal to external is done on NAT router at the edge of LAN
NAT router will have a private IP address and a public address from the ISP
Prevents malicious activity coming from outside hosts
Improves reliability of the network by isolating the network from external intruders
Two main NAT type – static and dynamic
Static NAT – a fixed public IP address
Dynamic NAT – Private IP address is mapped from a pool of registered public IP addresses

6. IPv6 Addressing 128-bit address space (8 groups of 16- bits)
64-bit network prefix and 64-bit host prefix
340 billion billion billion billion – enough to supply 75 IP addresses to every sq. inch
IPv6 has four address types
Unicast (one-to-one)
Anycast (one-to-nearest)
Multicast (one-to-many)
Reserved

7. IPv6 Addressing Benefits of IPv6 include NAT64 – IPv4 to IPv6 NAT
Improved routing efficiency for simplified header format
Offers better security mechanism by using Encapsulating security payload (ESP) where recipient requires proper key to unscramble the data
NAT64 – IPv4 to IPv6 NAT
IPv4 to IPv6 transition
Dual-stack network – both work in tandem
Tunneling – one protocol encapsulating the other
Translation – IP header and addresses of one translated into another

8. DNS
DNS provides translation between host names ( and numeric IP addresses ( and for IPv4 service)
The name portion of the URL - google is resolved into IP addresses
13 root domain servers of ICANN contains list of
IP addresses of global registries and
250 country specific registries
Top domain names
.com, .mil, .gov, .edu, .net, .org, .int

9. Next generation of internet (NGi)
Interplanetary Internet (IPN)
A network of internets located on planets, moon or abroad spacecraft
Must allow long transmission times, bandwidth constraints, blockage, lost data and constantly moving sources
Internet-enabled devices
Mobiles, palm devices, Smart TV, smart watches, smart vehicles and household appliances
RFID applications
Transportations, consumer products, drug and food IDs and shelf life indicator, patient identifier, intelligent wearables
Session initiation protocol (SIP) telephony
Voice and multimedia communication such as instant messaging, speech-to-text functionality
It can support unicast and multicast operation
Digital objects and libraries
Digital object-identifier is used to uniquely identify an object where metadata contains the relevant information about the object (e.g., )
Semantic Web
Providing meaning to the content of a document so that machines can understand
Search by businesses versus scientific data, an author versus an entertainer
doi: /182