In this video we're going to discuss writing.
We look at the basics of IP writing and look at different routing protocols including distance vector
and a linked state writing protocols with compay the differences between distance vector writing protocols
such as rip and link state running protocols such as OSPF.
We'll also discuss some of the methods that distance vector writing protocols use to stop loops writing
protocols are very important because they advertise networks and use various mechanisms to prevent loops
before discussing writing protocols such as always.
All right Joe A-P you need to know the difference between a raftered versus a routing protocol.
You should also be able to differentiate and explain the advantages and disadvantages of using static
routes versus dynamic running protocols.
So why would you want to use a static route versus a dynamic writing protocol such as always B.F..
And as mentioned we want to talk about distance vector and link state running protocols.
So what is the difference between a routed protocol and a rough protocol.
Now a rotted protocol a use the data.
Examples would be IP version 4 or IP version 6.
When you use a Hialeah protocol such as HGP or ATP that protocol is using a lower layer protocol such
as IP version for IP version 6 to carry the user data from one device to another.
So when you connect to a Web site and you're viewing a web page that would be deemed to be routed data
data from the web server is being routed to your PC.
Now the addressing scheme used to buy routed protocols is based on the specific protocol such as IP
version for using a 32 bit address and IP version 6 using a hundred and twenty eight.
But address now how do routers know where devices are in a network.
As an example my PC is based in the UK but when I go to Facebook com traffic is sent from my PC to Facebook
based in California and back again.
How does my device actually reach the Facebook servers in a data center in California.
And how does the data get back to my PC in the UK.
How is the user data forwarded from one device to another.
Now it's important to realize that every router along the path between my PC in the UK and Facebook
does come makes an independent routing decision as an example if I trace to Facebook dot com.
And in this case I'm going to set the time out to a low valley such as 50 milliseconds.
Traffic is being forwarded from my PC on a hop by hop basis from one router to the next until it hopefully
reaches Facebook dot com.
Every one of these hops is an independent router making independent routing decisions.
Now Facebook and a lot of other big Web sites will have data centers scattered around the world.
So my traffic may not actually be going all the way to the U.S. but maybe going to a local data center
in Europe.
That all depends on how the network is configured.
These riding decisions made by rodders is known as the hop by hop rotting paradigm with unicast traffic
routing is based on destination address only not on source address.
Serratus decide which traffic goes based on the destination IP address in by example its address and
Rodders will decide wait to route traffic.
Based on the destination IP address and information stored in writing tables every router along the
path needs to determine an outgoing interface to forward traffic to reach the destination IP address.
To do that routers communicate information about networks using routing protocols.
They will then determine the best path to the destination IP address using criteria specific to that
individual rodding protocol.
As an example RP uses hop count to determine the best path OSPF uses the bandwidth of interfaces to
determine the best path.
The GOP uses bandwidth and delay to determine the best path.
So running protocols are used to automatically advertise networks between routers and that's how rodders
learn about the available networks in a topology.
It's also important to note that if a router doesn't know about a destination IP address.
In other words information about vector destination IP address is not in its routing table.
It will drop unicast packets destination IP addresses are matched against networks and subnets in the
road as a writing table.
So if a router receives traffic going to an IP address of let's say ten to one that wanted one but that
IP address doesn't match a network in the rodders writing table.
The Rato will drop the packets because it doesn't know where to forward them.
Essentially if you tell Harada send traffic to IP address or tendered wondered wondered one and the
router doesn't know how to get to that network or IP address the router will drop the traffic if there
is no matching rot in the writing table.
Traffic gets dropped.
This applies specifically to unicast packets where we are doing our routing based on destination IP
address.
So in summary writing protocols allow Radice to learn about Destination networks that facilitates the
exchange of a rafted information between devices.
Routers can dynamically learn about networks in the topology and can then make routing decisions based
on different criteria such as bandwidth hop count or delay to determine the best path route is then
simply choose an outgoing interface based on the writing table and will then forward packets out of
that interface to reach a destination.