2. Overview of Transport Layer
Make communication among
applications running on different hosts.
Sender Side: breaks applications messages into
segments
Receiver Side: Reassemble segments into
messages passes to application layer.
3. Network graph:
Forward’s packet lowest cost path.
Can calculate shortest path and load them into non
volatile storage.
PROBLEMS:
1.Does not deal with node or link failure.
2.Does not consider addition of new nodes or link.
SOLUTION:
I. Distance vector routing algorithm.
II. Link state algorithm.
4. DV algorithm: (bellman ford
algorithm)
Router sends its table to its neighbour for every t
seconds
It updates the table based on new informations.
COUNT TO INFINITY:
when the number of hops counts more
than one it is said to be count to infinity.
5. RIP- ROUTING INFORMATION PROTOCOL
Straight forward implementation of distance vector
routing.
Sends an update message for every updates .
SPLIT HORIZON TECHNIQUE:
• achieved by poison reverse.
• prevent loop in routing.
• information about the routing for a particular packet is
not sent in same direction.
6. RIP V2 packet format
Command version must be zero
family on net 1 route taps
Address prefix of net1
Mask of net1
Distance of net1
family of net2 route taps
Address prefix of net2
Mask of net2
Distance of net2
7. LINK STATE ROUTING:
Send to all nodes information about directly
connected links .
LINK STATE PACKET (LSP)
ID of the node.
Cost of link to each directly connected nodes.
Sequence number.
Time to live (TTL).
RELIABLE FLOODING :
Stores , forwards, generates the LSP.
Sequence no= 0 , when reboot.
8. GLOBAL INTERNET PROTOCOL :
NSF NET
BACKBONE
BARNET
REGIONAL WESTSIDE MIDNET
NACR LA
STANFORD BERKLEY UNIV FS
10. AUTONOMOUS SYSTEM
( ROUTING DOMAIN)
Corresponds to an administrative domain.
Eg. University, company etc….
NETWORK WITH 2 AUTONOMOUS SYSTEM:
R1 R3 R5
R6
R2
11. INTER DOMAIN ROUTING
PROTOCOLS:
EGP- EXTERIOR GATEWAY PROTOCOL.
BGP- BORDER GATEWAY PROTOCOL.
BGP:
It is a collection of set of ASS.
internet consist of connection of multiple
backbone networks called service providers.
service provider may be private or government
.
backbone backbone providers
small providers
companies
large companies ISP
consumers
12. BGP4:
it defines local traffic as traffic that originates at (or)
terminates on nodes within autonomous system.
Transit traffic – traffic passing through AS.
Types of AS :
Stub AS
Multihomed AS
Transit AS
13. Stud AS:
single connection to one other AS.
carry only local traffic.
eg- small cooperation.
Multihomed AS:
connected with more than one other AS.
refuses to carry transit traffic.
eg- large corporations.
Transit AS:
it has more connection and designed carry
both transit and local traffic.
(backbone)
14. AS :
• it has speaker .
• Has one or more border gateways which are
routers.
• Through routers packets leaves AS.
• It advertises complete path with list of autonomous
system to reach a particular network.
BGP issues:
1. AS number should be unique.
2. AS number are 16 bits number assigned ny a
central authority.
15. Internet Protocol Version 6 (IPV6)
128 bits
It is a next generation IP.
Supports real time service.
Supports multicast.
Supports authentication and security mechanism.
Supports auto configuration.
Enhance routing functionality including support for
mobile host.
Address notation
X:X:X:X:X:X:X:X
16. IPv6 header
Version Traffic Flow label
Payload length Next header HOP
Source address
Destination address
Header data
17. Internet Multicast:
one to many multicast.
One to many multicast:
Source specific multicast(SSM) :
A receiving host specifies both a multicast
group and sending host.
Many to many multicast (ASM):
A host signal decides to join or leave a group
by communicating with its local route using special
protocol.
18. IPv4 IGMP ( Internet Group Management
Protocol)
IPv6 MLD ( Multicast Listener Dictionary)
TYPES:
1. Distance vector Multicast Routing Protocol:
router already knows the shortest path through
the source n goes to router n.
it eliminates broadcast packets by
parent for LAN (relative to S) forward
Shortest path to S (leave via DV)
Smallest address to break ties.
19. Network layer :
IGMP ICMP
IP ARP
each multicast router needs to know the list of
groups that have atleast one loyal member related to
each interface
Collection of this time of information is alone at
two levels .
a. Locally IGMP
b. Globally DVMRP , PIM
20. Common multicast protocol:
multicast
protocols
Source group
Based
based
MOSPF DVMRP DM SM CBT
DIM
DVMRP- an interior gateway protocol.
only rout multicast datagrams.
IGMP – used for discovery of host in multicast group.
DVMRP routs multicast datagram within an AS
21. DVMRP – Packet
Type – indicates it is a DVMRP packet.
Code – indicates the type of DVM of the packet code
Checksum – to detect error.
Minor and major versions – indicates the current
version of DVMRP.
Minor = 0XFF Major = 3
Type Code Checksum
Reserved Minor version Major Version
(0xFF) ( 3 )
This is portion of packet
22. PIM – Protocol Independent
Multicast
0
31
PIM- DM ( dense multicast )
Implicitly built’s shortest path tree by flooding
multicast traffic domain.
PIM-SM (sparse multicast )
Explicitly built’s shortest path tree to a route for
group and creates shortest path tree .
Version =2 Type Reserved Checksum
message type
