1. COMPUTER NETWORKS
CS610
Lecture-41
Hammad Khalid Khan

2. Review Lecture 40 Routing in The Global Internet
Autonomous System Concepts
IGP & EGP
Optimal Routes

3. Routes and Data Traffic
Each ISP is an autonomous system that uses an Exterior Gateway Protocol to advertise its customers’ networks to other ISPs
After an ISP advertises destination D, datagrams destined for D can begin to arrive

4. Routes and Data Traffic

5. Internet Routing Protocols
Border Gateway Protocol (BGP)
Routing Information Protocol (RIP)
Open Shortest Path First Protocol (OSPF)

6. Border Gateway Protocol (BGP)
Provides routing among autonomous systems (EGP)
Policies to control routes advertised
Uses reliable transport (TCP)
Gives path of autonomous systems for each destination
Currently the EGP of choice in the Internet
Current version is four (BGP-4)
Facilities for Transit Routing

7. The Routing Information Protocol (RIP)
Routing within an autonomous system (IGP)
Hop count metric
Unreliable transport (uses UDP)
Broadcast or multicast delivery
Default Route Propagation
Distance vector algorithm
Passive version for host

8. Summary Routes and Data Traffic Border Gateway Protocol
Routing Information Protocol