Cisco - CCENT/CCNA R&S (100-105) - Static and Dynamic Routing .30

[Music] hello and welcome back to the C cent journey with me right in this next section we're going to continue with the routing section of the C sent or icnd1 and we're going to dive deeper into understanding static and dynamic routing for a very high-level point of view in the last video we talked about why routing was needed and we jumped on to packet tracer and we went through the verification steps to understand what was missing and how we would get traffic off the local network so let's go over static and dynamic routing for those who don't know you can contact me here on YouTube or LinkedIn or Twitter so let's start by having a high-level discussion about static and dynamic routing and here we're going to begin with static routing so first of all what we want to know about it is used in smaller designs so we've got two or three Reuters and they're not doing anything fancy then let's not overcomplicate things let's add static routing as network engineers you realize that the more and more you design the best approach is always the simplest approach the downsides of static routing is it does require hands on to set up and hands on to maintain and it's not dynamic so a good floor to explain with static routing is let's say we have a Rooter connected to a switch and on the back of that switch we also have a never Rooter now this is something we're going to go into a bit more depth but I'll give you a high-level view now let's have a think of what we know already between these two rooters we know that this link to this link there are layer 1 and layer 2 checks ie isn't plugged in is it Ethernet if I disconnect this cable we know this interface will remain up because the link to the switch is also up well this here actually identifies one of the biggest flaws with static routing without adding any additional intelligence if I was to add a group to tell this Rooter if you want to access network X which is off the back of this Reuter go towards this next hop providing the link towards the switch is actually up it will try to route that traffic even though the link between the switch and the end destination is actually down so because of that we will need to add some sort of intelligence like IPS leh or track statements to actually ensure that this route is able to confirm connectivity end-to-end before using that static route if we used something like dynamically routing in this scenario then we would have some sort of keepalive mechanism between the two endpoints through the switch this means that if the link were to go down here then no keeper lies will be sent from the router to this Reuter and as such the route can be removed and traffic will not be sent and in turn will not be black hold this is think will go into a bit more detail but it's very important to understand how routing is affected on a per hop basis depending on which technology ie static or dynamic routing you use to achieve a particular goal it is always preferred by default over any other dynamic routing now route selection is something we've not talked about and it will be in the upcoming videos where the route itself goes through a selection process because a route are when it runs its process it can run a bunch of dynamic processes and static routing so for example a Rooter can run rip the routing information protocol which is a variant of dynamic routing it can also run simultaneously OSPF the open shortest path first protocol which again is a dynamic routing protocol and it can also run static routing if it has one of these processes learning all different routes all of them are presented to the router and the route earth makes a decision based on a set of rules and those rules can be determined and changed by administrators however by default it's always going to prefer a static route over a dynamic route and when I say that I set with Klaus because like most things in networking there's always it if and above and here what we're saying is we always prefer static routing over dynamic routing if nothing has changed so hence that by default and if the root is the same length so if I learn a slash 24 via rip the same slash 24 fios bf and the same slash 24 v static providing nothing else has been changed I will prefer the static route selection process as I said we'll get into in a more depth later because it can get complicated but we will understand the very high-level basics which is required for the icnd1 or the CCENT next is because it's always preferred by default we can use it to bypass around certain challenges or for quick traffic engineering so for an example let's say we have a couple of rooters connected like so and all these route is a running rip the routing information protocol which again is a dynamic routing protocol this means that each route app is talking to one another in the rip language and telling each other how to reach their subnets so let's say we have subnet Y subnet V and subnet X every router knows how to reach every other subnet because of rip well let's say for example that this router has both Y and Ed and this particular path here is the best path that rip has picked for any traffic from X to Y or Z this means that the link to V and up as in these two links are not being utilized for any traffic between X Y and Zed however let's say as an engineer we're paying for these two links and we want for example any traffic to the Z Network to root over this link what we can do is on this particular Rooter we can set a static route could push the traffic to V and V in turn will push it to the path as Zed this will help us overcome some quick traffic engineering to change the particular path however when we make these sort of changes we need to keep in mind a few things first of all we need to make sure that there is some sort of mechanism to track the route because if the path were to go down let's say here you want to make sure that traffic can fall back to the original path via rip how is it actually set up very simple we go into the config the global config and we type in the click keywords IP route we use the destination network and destination subnet mask and then we point it to the next hop so if we have two Reuters and these two Reuters are connected through a network let's say 192 168 0 0 slash 30 here is that one here is dot 2 and behind this router we have let's say 10000 / 8 well we can go on to this router and we can simply say IP route 10000 255 0 0 0 with the next hop of 192 168 0 2 now notice that we use the remote IP on the link we do not use our own IP so that's the first key bit we have to use the remote IP where we talked about static routing in more detail as we move on of course we understand why that's important that we have to use the next hop and it's important why we use an IP address and we don't specify the local interface and just below you can see I've got another example here so this is kind of the reversible we just done in a sense this is saying if you want to get to the 192 168 0 / 24 Network go to the next hop of 10-10-10 1 so all out the verification side of a few commands here we have show IP route this was the command that we used in the previous video to look at the routing table but we can put the keyword of static on the end which says show me the route that I've actually got which are static so it kind of filters out the routing table for us we can do the same command show IP route but we can filter based on a prefix so if we put this command in and we then said show IP route 192 168 1 1 1 2 1 5 100 anything in this slash 24 then it will tell us how the Rooter has installed that route is it 5 static is it via a dynamic routing protocol is it directly connected it will give us a bit more information around some attributes of the link such as which which is the ad which is the metric and anything else that may be applicable to that particular route type we can then also do the show running config obviously show one conve will show us the entire config but then we can use this thing called a pipe and pipe it to include only the keyword of IP route something which is worth mentioning is in an ideal situation we should really as engineers be avoiding the running configuration as a verification tool because the running configuration shows us the configuration it does not show us the output or the impact of that configuration so an example of that if we done the show running config include IP route it will rightly so show us the IP route command that we typed into our router however what it won't show us is whether that command is taking effect and what impact that command actually has on us so in order to do that we would need to use the correct verification command in order to see the output of that command only because it's in your running conflict does not mean it's actually taking effect there's key distinction to be used there a lot of engineers look at the running config they see it's there as a part of the configuration and they believe it's in place don't get confused between configuration and verification moving on to dynamic routing so dynamic routing is used where static routing is not in basically all other design cases from small enterprises to large service providers most of the networks it be working on would be using dynamic routing and then static routing will be used in different parts of the network or as we've seen just now as a traffic engineering tool to achieve a certain goal before we continue with the presentation let's have a quick high-level view of what is dynamic routing or in the previous example we had that triangulation between three rooters and we said that these route is where let's say brew - a brew to be a memory to see and off the back of them they had different subnets let's say subnet Y X V and W random characters and the way it would work would be as we enabled our routing protocols on these interfaces connecting between the actual rooters themselves let's say for example that's rip rip we'll start sending out their packets advertising all the routes that each router is aware of and eventually once those packets are sent to each other any router will have access and some sort of path towards any other network so network the V will have a path towards X and then through some sort of calculation they will decide which is the best path so for example let's say V want to speak to X it knows that it is directly connected to X through route a and it knows this is the best path rather than going up through to see across to a however if this path were to go down after a set period of time it will then know that it can reach X through a alternative path towards X via C and if the path were to come back then it can use the better path and it will dynamically flip back and forth ensuring there is full reach ability without any administrative overhead so let's continue having a discussion around dynamic routing dynamic routing also has two sub categories which is a GP and EGP IGP is the interior gateway protocol and EGP is the exterior gateway protocol now for the CCNA you're primarily focusing on a GPS these are protocols such as RIP OSPF EIGRP and within the SI sent or icnd1 only a rip is part of the actual syllabus you need to be aware of OSPF and EIGRP in the sense of understanding route selection when they're included but as far as the configuration and verification is concerned rip is the only one on the official icnd1 blueprint and there's the other category called e GP which only has one protocol which is BGP the border gateway protocol so let's have a discussion very briefly around the differences between an AI GP and an e GP an IDP as I said is an interior gateway protocol and in eg P is an exterior gateway protocol now interior and exterior with protocols are different they behave completely differently and they're used in different scenarios now if you have a think about a network let's say this network has a bunch of rooters in it and they're owned and managed by a single person this is referred to as an autonomous system a single administrative control for the entire network within the autonomous systems we would normally run some sort of ITP protocol so as previously mentioned these IDP protocols are things like the rip process or the routing information protocol OSPF open shortest path first key i GRP the enhanced interior gateway protocol and this is what's used inside the autonomous system so they don't need to match and they don't need to communicate so maybe this network down here is running rip and OSPF and this network up here is running rip and EIGRP well what we could do then is we would have to run some sort of protocol between the timer systems in order to connect them up because you think about the Internet the Internet is a bunch of autonomous systems a bunch of single administrative controls different companies connecting together to form one giant network and the EGP which we said earlier which is actually only one BGP will be used between the autonomous systems now one thing to keep in mind is even though we say BGP is an DGP and rip OSPF and so forth IG PS there is nothing stopping us as administrators to then adopt BGP within our network or some oddly designs you might actually have some sort of igb between different autonomous systems however as far as the C set is concerned as far as icnd1 is concerned there are two subcategories I GP and EGP IGP issued within an autonomous system and a GPS are used between atomic systems and an autonomous system is a single administrative control whether that's a single company that has a huge network or whether that's a single person that controls multiple networks both dynamic and Static can be used together and even multiple dynamic on a single device we said this before then you can have rip OSPF EIGRP and static routing all on the same route are very rare case that you would have that but there is an option it's something to be aware of if you have some sort of we call redistribution point ins let's say you have a network that's running rip on these two links between the rooters and then you'll have a different part of the network which is running a I gr P over here then you need the root in the middle to actually won both ER GLP and rip as it moves routes to and from rip and the edge ERP and this is referred to as redistribution which is something outside the scope of the CCENT and potentially the CCNA but let's think that you need to be aware of that if there are multiple routing processes on the router what are we actually going to prefer and why different dynamic routing protocols like ER jarppi OSPF rip offers different benefits and those benefits depends on the actual design you're looking to achieve that's something that doesn't go into the CCENT in detail because like I said we only need to be aware of these routing protocols the one that we need to be fully comfortable with is rip we need to know how to configure it how to verify it and how it affects routing based on its behavior and how it interacts with other protocols and static routing so what about the configuration of this well here's a quick example we first of all go into the global config we type in Rooter and then here we use either OSPF EIGRP and so forth but you can see we simply select the rip process for now it poses into a sub configuration mode where you specify network and then which network you wish to enable the process on now what this actually does this network command is go off and it looks at your connected interfaces and it finds the interface that has the 1000 network on let's say fastethernet 0/0 and it starts the rip process so actually start sending rip data or rip packets out by interface towards a neighboring device and obviously when we get into rip in more detail we'll go through the configuration and the verification here I'm using rip as an example of how you enable dynamic routing then how would you verify it we can look at the routing table again but this time instead of static we can put in the routing protocol are interested in we can look at the route that we're actually specifically interested in so if we were to do sheriff route let's say 10 then it will tell us that we've learned a rip route out by interface and the details about that rip route like for example the metric again we can look at the running config to look at the configuration to confirm that we've typed it correctly it won't tell us if it's been applied and whether it's functional but it'll tell us does it actually exist in the configuration and then show a few protocols this will tell us things such as what networks have we enabled the rip process on what are our timers for the protocol and much more information and some of the output change depending on which dynamic routing we actually choose to use okay so that's always got time for in this lesson in the last video we talked about why routing was needed we looked at the routing tables and notice that Reuters only install that directly connected networks and if we want to get off our directly connected networks to a remote network then we need some sort of static routing to tell the local route how to get to the remote network or we need some sort of dynamic routing for the two bridges to go to communicate to one another unable to advertise the routes that they are aware of we said that dynamic routing comes in two flavors I GP the interior gateway protocols which are things like rip OSPF EIGRP and then there is eg P which is the exterior gateway protocols which essentially there's only one which is Beach P we had a discussion between the differences between EGP and IGP we said that iGPS are used within those hollom systems within a network within a company and EB G and E GPS or BGP is used between the Tollan systems or between companies we also then looked at the benefits of dynamic routing and why you would want to use it we said that that I'm eight routing is dynamic in its right meaning that it doesn't require the administrator to do much work it will advertise the routes so everyone is aware of everything and then we can as we wanted to sue some traffic engineering over the top to control which paths are use and which paths are not used in the next video we'll go over path selection and we'll go into actually configuring static and dynamic routing I hope this videos been informative I like to thank you for viewing and if it has been please do like and subscribe

Channel: Ryan Beney

Views: 14,689

Keywords: dynamic and static routing, dynamic routing overview, what is static routing, what is dynamic routing, how to configure static routing, how to configure dynamic routing, static routing vs dynamic routing, ccent full course, ccent certification, ccna full course, ccna routing and switching, ccna 200-125, igp vs egp, igp vs bgp, static routing tutorial, static routing configuration, dynamic routing protocols, dynamic routing tutorial, ccent routing and switching

Id: CQtBADLsyis

Length: 24min 6sec (1446 seconds)

Published: Sun Apr 09 2017