This document discusses different types of routing including direct, indirect, static, and dynamic routing. It describes the fields in a routing table including mask, network address, next hop address, interface, and others. Finally, it explains how routing tables are populated with routing information and provides an example routing table for a router.

1. Routing

2. Contents
 Different type of routing
 Fields of routing table
 Forwarding technique
 Populate a routing table

3. Different types of routing
 Direct routing
 Indirect routing
 Static routing
 Dynamic routing

4. Direct and Indirect Routing
 When routing is performed in the same network than
direct routing happens. Performed by Host.
 Destination network = local network
 Indirect routing performed from one network to
another network.
 Destination network ≠ local network
 Packet is forwarded to default gateway

5. Example of Direct & Indirect routing

6. Static and Dynamic Routing
Static routing :
Can be set as permanent (will not be
removed
-If interface goes down)
- Only way for certain technologies
Dynamic routing :
Adapts to topology changes

7. Fields of Routing Table
Mask Network
address
Next-hop
address
Interface Flags Referenc
e
count
Use
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8. Short Description
 Mask: Used for entry
 Network address : Defines where the packet will
delivered.
 Next-hop address : defines the address of the next router
 Interface: Shows the name of interface
 Flags: U(up)-The routing is up & running
G(gateway)-The destination is another network
H(hop-specific)-Host specific address
 Reference count :Gives the number of router users at a
moment
 Use :shows the number of passed packets through
router.

9. Packet Forwarding Techniques
 Next Hop Method
 Network Specific Method
 Host Specific Method
 Default Method

10. TCP/IP Protocol Suite
6.2 FORWARDING
Forwarding means to place the packet in its route to its destination.
Forwarding requires a host or a router to have a routing table.

11. Next-Hop Method Versus Route Method

12. Network-Specific Method Versus Host-
Specific Method

13. Default method

14. Populate a Routing Table
A network router sends packets to remote network
sites based on information in its routing table. This
table is like an index that has an IP address, a MAC
address and an interface number

15. Populating a routing table from following figure

16. Routing table for Router R1
Mask Network Address Next Hop Interface
/26 180.70.65.192 ___ m2
/25 180.70.65.128 ___ m0
/24 201.4.22.0 ___ m3
/22 201.4.16.0 ___ m1
Any Any 180.70.65.200 m2