CCNP ENARSI - 1.4 Troubleshoot Redistribution - EIGRP & OSPF Lab

welcome to another video from yourit explained in this video we're going to go through the redistribution between eigrp and rspf for the nrc exam so we're going to be posed with a few potential problems and we're going to troubleshoot them in ways that you may be expected to know understand and be able to perform on your own so what you see on the screen is all configured so far we've got the ip addresses configured the routing protocols configured what we haven't done is the redistribution between the two protocols on router 5. so let's just do a quick verification if i go to router 4 i'll open up a console session and let's see what is going on on this device let me just clear that a little bit and do a show ip route so on router 4 which is over here we can see that it has an rspf route that it's learned because it's not directly connected being 172 1600 so ospf is up and running and it's got obviously the connections for its local subnet so it's all working as we would expect and hope so definitely everything is configured ospf and ergrp just the redistribution between the two is not configured so round three and four won't be out of reach router one and two at the moment or those networks on or vice versa either i'll just prove that so let's go to router three do a quick little ping to 10.00.1 so that's this interface over here on router 1. yep and it's going to fail so i'll just send that okay so let's dive straight into the configuration now of the route redistribution so it's going to reload uh let's clear the sorry a little bit and now configure terminal and let's go because i can i want to do it both ways i want to redistribute ergp into ospf and ospf into ergrp so first let's go eogrp into rspf that's what i'm going to configure so all the ergrp routes are going to be redistributed into rspf and to do that you go into the protocol that you're redistributing into so i'm going to go to router ospf process id1 that's what i'm running and in ospf i'm going to redistribute ergrp into it so now to start to type redistribute you can see you've got a a list of options here that we can choose from we want to redistribute eigrp autonomous system 100 is what i'm using for ergrp and then there's a few other options hopefully you identify the one from the previous theory video and what we're meant to use but what you can actually do is just leave it like that and press enter and it's not going to have any issues so now if i go onto router 3 open up a console there let's have a look is it now picking up the ergrp routes that have been redistributed into rspf show ip route yep sure enough we've got these ospf external type 2 routes here which are those networks we can see over on the left so you might be wondering oh why aren't they coming up as ergrp routes well that's because that's what redistribution does it redistributes other routes into rspf so make some rpf routes and we just distinguish these from regular routes by adding external type 2 or external type 1 to denote them which you can see from the codes in the table up here in the ip routing table okay and you might be asking well you didn't do that keyword you didn't specify up here on router 5 you didn't type in subnets right um show the list subnets and let me just show you something very quickly we'll go end and go show run and begin at rpf and now at ospf have a look at this redistribute eigrp 100 subnets this is now the default behavior it'll automatically add in subnet so you can type it out if you want but you don't actually have to so most modern devices will just add that in for you now so that it'll include classless addresses because that's just there's no point not to anymore all right so now let's go the other way we now want to go rspf into ergrp so let's go configure terminal and then router eigrp because we're redistributing into elgrp on system 100 and then same thing redistribute ospf process id 1 and then we do have other options but i'll just press enter same as we did on the other device right now we are hoping that the ospf routes have been redistributed into ergrp just like we did on the other way if i go to router 2 open up a console session let's have a look show ip route it doesn't have it it hasn't picked up any new routes it's only got those connected and local routes so it would have eigrp routes as well but the only two networks are directly connected that's why they're not showing as let me show you on router one so you can see that there's definitely ergrp process running so i go end and show ip route here we are ergrp 101010 0 24 down here router 1 has learned it through esgrp so it's definitely up and running no worries no issues there but it's not picking up the ospf routes and this is because of what we covered off on in the theory lesson previously that is because when you redistribute into eigrp the default metric is infinity and you if it's a default metric of infinity that means that the metric is unreachable it yeah that's why the routes are not coming up but the other way when you redistribute into rspf the default metric is actually 20. let's just verify that so if i go to router 3 or 4 so i'll go three let's have a look so this line here it's picking up that 101010.0024 network it's got an admin distance of 110 and the default metric of 20 has been applied as you can see now the only time that's different is if you're redistributing bgp into rspf in which case the default metric is actually one right so that's the difference between these two protocols so if we want to fix this we do want spf routes to go into ergrp let's troubleshoot let's just go around a five let's end now let's have a look what's currently in the config so show run let's begin at ergrp and we can see we've got the networks advertised the autonomous systems specified and then we're just redistributing same is pretty much what we're doing in spf and although spf does have that extra default subnets word but we know from the previous lesson that ergrp needs more information because the infinity metric is not going to help us at all we need to actually specify the metric so let's do that now configure terminal router yeah grp tunnel system 100 redistribute all spf process id 1 just as we did before but now let's have a look what other options we have so you could you could do this through a route map if you want to as well and you may be post scenarios where they are doing it through a route map in your examinations or whenever you're working as a network engineer but what we are carrying what we're going to do here in this specific environment is we're just going to specify it per route or per redistribution on the device so we're going to go straight away to metric now that's i'm just going to go through the same way i would recommend you do this and you just type in question mark after each line because there's a fair bit to get through so firstly it's going to ask for the bandwidth metric in kilobits per second kilobits per second so i'm gonna do one million one one two three one two three because one million kilobits a second is a gigabit per second so i'm happy with that what's next yeah eigrp delay metric in 10 microsecond units i'm happy with just no delay pretty much so let's just go with the 10 microsecond delay next reliability metric where 255 is 100 reliable well i'm pretty happy with my configuration here in this lab environment for it to be i'm going to say it's 100 reliable right i'm i'm happy to leave it like that next eigrp effective bandwidth metric where 255 is 100 loaded well as i said i'm pretty happy with how it's all configured so i'm going to go not load it at all just go down to one now lastly the mtu of the path now again this will change depending on your environment so in mind i'm happy to just keep it as the standard 1500 but if you're using additional headers or anything like that then you may have to reduce this to a different number depending on what your um what your specific scenario is right what's after that well then it just goes back to those other options of match and route map so from here let's press enter so we've done redistribute ospf 1 metric one million one two five five one fifteen hundred now let's now we've done that this is on router 5 by the way because this is all happening on this device that connects the two routing protocols together now let's have a look if these devices router 1 and 2 are picking up the lspf routes i'll go to router 2 and let's just refresh the same command show iprout voila we are now picking up ergrp external routes as you can see here so they've got the 170 admin distance because they are external ergrp rounds not internal so if we go to router 1 let's have a look at the difference there so router one is picked them up as well but here's just a regular uh eigrp route which has a admin distance of 90 but these have 170. so this is again referring back to the very first lesson in the series we went through admin distance it's you got to have that holistic approach to anarchy you've got to understand at least the basics of everything in here so that you get the full picture when troubleshooting right and then you can see the metric afterwards so now hopefully we should be able to ping between the devices so did i try that on this yet router three let's see router three let's do a ping to let's go router one the furthest uh interface over there so round of three we're gonna ping 10.10 oh sorry 10.0.0.1 success excellent so it's all working as we would have hoped so now we've successfully done route redistribution or mutual route redistribution between ergrp and ospf now it can get more complicated if you start to throw in route maps and defining a default metric which then applies to others there's many different ways to do this but this is just the basic configuration and probably the most common fault that people will run into with this now we're just going to go on to something a little bit different and it's the way that the routes uh redistributed into rspf specifically so let's have a look at round three and round four on the screen and if they want to reach the 10.000 network you would think that router 3 should be advertising a better path or it should be saying i am the better choice so if you've got a client let's say an imaginary little client that's just hanging off of router 3 and 4 and it wants to reach the 10 0 0 0 network it should go via router 3 every time because that's a shorter path router 4 just adds an extra hop going by router 3. but because of what we've done they will both advertise it the exact same way let's just confirm so on round three if we look at the routing table up here i'll actually i'll just rerun the command so you can see it again so we want to reach that 100 network it's got an admin distance of 110 as that's uh the default admin distance of an ospf external type 2 or external routes they take on the same admin distance of regular ospf and then it's got the default metric of 20. now if i go to router 4 let's have a look on here open up a console and show ip route if we have a look at the routes to that same network it's pretty much the exact same it's got that 110 admin distance and a metric of 20. so router 3 and 4 are saying hey it's the exact same whether you go via 3 or 4 it's going to be just as quick which we know is not true we know router 4 is further away and so if you want to configure it to be more specific and accurate this is what you do so let's go back to router 5 where the redistribution happens that's where we're going to fix this issue because first let's have a look on router 3 and 4. we see these are ospf external type 2 routes now external type 2 will just use the same metric as the route when it was redistributed so for ospf uses a default metric of 20 when um redistributing routes in unless it's bgp which is one that's all it will use on every device external type one on the other hand if we look up in the table here it uses the default metric plus the internal metric and so that's going to be more accurate that's what we want to that's probably what we want here so if i go to router 5 we're going to go out of this one because we're redistributing into rspf again so redistribute ergrp total system 100 let's just type it in subnets doesn't matter if we do a don't and now we have this other option here being metric type so this is where you specify type one or type two so let's change it let's make them type one because the default if you don't specify is type two so that's why we see those on router three it's um ospf external type two and on round fours external type two even though we didn't set anything specific to that before the default is to use type two we've now manually changed it to type one so let's go back through our three let's just refresh this and now we can see it's external type one same one router four refresh external type 1. now round off 3 we can see here the metric has changed so i've been distance still the same but the metric is now 30 because it's done the default external metric plus the internal so plus a 10 metric here and now if we go to router 4 we can see it's now 40. so they are now different it's still got that 20 plus the internal metrics of 10 here and then 10 here so now if there's a device hanging off of 3 and four round of three and four that is it will now know to go by router three if it wants to reach that network and so that's about it that's all that we really need to cover off on for eigrp and ospf redistribution it's really quite simple once you just wrap your head around the concept i will refer back to my previous example of comparing it to conversion so if you struggle with the concept of route redistribution think of it as as route conversion that's all you're essentially doing is you're converting from one random protocol into the other aside from that the future videos we'll just go through some of the other uh redistribution between different routing protocols thanks for watching and i'll see you in the next one [Music] you

Channel: Your IT Explained

Views: 21

Keywords: Ccnp, enarsi, cisco, exam, topics, troubleshoot, tshoot, aus, aussie, redistribution, redist, ospf, eigrp, gns3

Id: IpnNOPnb7Hg

Length: 19min 1sec (1141 seconds)

Published: Tue Nov 30 2021