Dynamic routing

Dynamic routing

1. Dynamic routing protocols

   • Overview of the dynamic routing protocol
     • Evolution of the dynamic routing protocol
       • Dynamic routing protocols are used in the field of networks since the late eighties
     • Dynamic routing protocol components
       • Routing protocols are used to facilitate the exchange of routing information between routers.
   • Comparison between dynamic and static routing
     • Uses of static routing
       • Before identifying the benefits of dynamic routing protocols, consider the reasons why network professionals use static routing
     • Advantages and disadvantages of static routing
       • Static routing is easy to implement in small networks. The static routes remain unchanged, which makes it relatively easy to carry out problem solving.
     • Uses of dynamic routing protocols
       • Dynamic routing protocols help the network administrator to manage the rigorous and slow process of configuration and maintenance of static routes
     • Advantages and disadvantages of dynamic routing
       • Dynamic routing protocols work well in any type of network made up of several routers.

2. RIPv2

   • Configuring the RIP protocol
     • RIP configuration mode on the router
       • Although the RIP protocol is used very infrequently in modern networks,
     • Network announcement
       • the router still needs to know the local interfaces that it should use to communicate with other routers
     • Verify RIP routing
       • The show ip protocols command shows the IPv4 routing protocol parameters currently configured on the router
     • Enabling and verifying RIPv2
       • it is verified that there are no RIP routes in the routing table. This is because the R1 is now listening for RIPv2 updates only.
     • Disable automatic summary
       • To modify the default behavior of RIPv2 for automatic summarization, use the router configuration mode command not auto-summary,
     • Configuration of passive interfaces
       • By default, RIP updates are forwarded by all interfaces with RIP enabled.
     • Propagate a default route
       • It is the perimeter router with a simple connection to a service provider.

3. The routing table

   • Parts of an IPv4 route entry
     • Entries in the routing table
       • in the beginning, the hierarchy of the routing table in the Cisco IOS was implemented with the classful routing scheme
     • Directly connected inputs
       • It has three directly connected networks. Note that when an active router interface is configured
     • Remote network entries
       • identifies the assigned value to reach the remote network. Lower values ​​indicate preferred routes
   • IPv4 routes discovered dynamically
     • Terms of the routing table
       • is a hierarchical structure used to speed up the search process when routes are located and packages are forwarded.
     • Final route
       • A final route is an entry in the routing table that contains an IPv4 address of the next hop or an exit interface
     • Level 1 route
       • A level 1 route is a route with a subnet mask equal to or less than the class mask of the network address.
     • Primary route level 1
       • The main routes are level 1 network routes that are divided into subnets.
     • Secondary route of level 2
       • is a route that constitutes a subnet of a classy network address.
   • IPv4 route search process
     • Route search process
       • When a packet arrives at a router interface, the router analyzes the IPv4 header, identifies the destination IPv4 address and continues through the router's search process.
     • Best route = longest match
       • So that there is a match between the destination IPv4 address of a packet and a route in the routing table
   • Analysis of an IPv6 routing table
     • IPv6 routing table entries
       • The components of the IPv6 routing table are very similar to those of the IPv4 routing table.
     • Directly connected inputs
       • Serial links have reference bandwidths configured to observe the way in which EIGRP metrics select the best route
     • Remote IPv6 network entries
       • router examines the level 1 network routes in search of the best match with the destination address of the IPv6 packet. As in IPv4