Advanced Cisco BGP Routing Protocol LAB - CCNP Level

hello there my name is mahar haddad today i'm going to show you how to configure bgp for advanced advanced topic for ccnp level so let's go to the website let's read the lab scenario you work as network engineer a company and you have a network under bgp tournament system too your company is connected to isp using two routers all ip addresses are connected so this is our topology we have isp here and this is our network router three four five everyone has loopback which belongs to the to the number of the router and then the router three and router four are connected to the isp serial interface serial links and then here is a capacitor net interface so our task configure eigrp one in your internal network without advertising the network connected to the isp so over here and we have we don't have to advertise these two links and ensure that you have full connectivity between router three four five do not advertise loopback one loopback two and loopback three should be here of router five into eigrp so this three loopback i look back one two three this ip address over here we should not advertise them into eitri all right so let's go to the routers three router grt one auto summary and network 192.168.35.0 then three for the zero and the loopback router before and look back router 5. c5 0 4 5 0. and look back zero and the other loop backs we should not advertise them all right so let's check if we have uh neighborship so router five form membership with router 4 and router 3 so it's ok router 4 with router 5 and router 3 and now the router 3 with the route of five and after four okay so if we ping look back off rather four rather five so we are okay so uh no need to do the others uh to do ping on the other loopback everything is okay so test one is done now task do to configure bgp in your internal networks in this area so all routers will have neighborship to each uh to each other on the loopback interfaces okay so on router three of course no auto summary and neighbor with loopback and i have to put also update charge look like zero enable i do the same router for okay rather high okay let's go to router 3 now and check if we form neighborship so router c4 navy ship was router 4 but not yet with router 5 sell active okay and prefix is 0 now you can see browser 5 is up with router 3. so also router 4 so ipvp summary also is ok router 5 also is ok okay we go to uh okay we configured this one now number three configure bgp membership between isp and connected router so they didn't say on the loopback so i would do it on the studio interface so isp i go to the isp router bgp one here no auto summary neighbor 192 uh the three remote autonomous system three and then to router 4 we have to do it on the on every router of course after pgp 3 then our router 4 a remote autonomous system one so uh we can see that router 3 has formed neighborship with router 1. let's check router 4 also quarter 4 not yet but we have to know that bgp is very slow uh routing a protocol because it's a it's a routing protocol for the internet and uh yeah we have to wait a little bit okay now it's up okay so now we can see that there's neighbors between routers 3 and isb and router 4 and rsp all right now advertise all loopbacks into bgp ensure that every router can reach the loopback of any router if not then solve the problem alright so we have loopback here isp 1.13 and year four and then we have a router five all digital packs so as we are on isp let's go to router bgp one and then network mask two five five two five five two five five two zero then router three network mask 255.0 router 4 rocker five mask 2.0 3.0 to be sure that i have created the loopback let me check yes they are here all right so now we have advertised all the back we have to be sure that we can reach any loopback from any router so uh let's try from okay let's uh first check if on isp we have the advertised loopback are shown on the isp so yes they are shown over here so uh if we do show ipr out of course we can see them into our routing table you can see bgp b is bgp but first of all uh this is isp and then we can check router 5 show ipvp so here there is a problem that you can see the the router 5 cannot find 1.1.1.1 there is missing of this greater sign which is best this one and the reason why is because the next hop is for this network is 192. i say the 13.1 13.1 is this interface over here so rather five doesn't know about this interface so what we have to do we have to go to router 3 and other four and say that they are then the next hop itself that's first thing to do so let's go to router 3 and here i say neighbor 525.5 and next hope self copy this one i'll do the same on router 4 okay now if i go back to router 5 so i pvgp then now you can see [Music] it's shown uh this greater sign now if i try to ping 1.101 which is isp i'm not able to and now it's not because it's not because the next next hop self it's because [Music] router 5 is is going to routers it's going to rotary but the router 5 doesn't know this or this [Music] links on hbgp so what we need to do we have to advertise these two links into pgp so uh i can do it on router 3 and under outer what i have what i will do i would i would advertise all the links so everything will be working because also later isp will not be able to reach router 5 because he doesn't know about these two links but let's try first on router 5. i'll go to isp for example here and i will say router bgp1 and network 192.168. 13.0 mask 25550 and then 40 into zero okay now if i go back to router 5 i do show ipvp so 13.0 is shown so now let's try to ping 1.201 it's not able uh i think it should be advertised also from routers 3 and router 4. so i will advertise all of this router 3 and router 4. here i will say network 192 168 0 and a router 4 i'll say network too much created 14.0 mask 2.5 to 2 i go back to router 5 now still not able all right i will advertise this thing this and this thing as well network 192.168.1 34.00 then another four that's zero up then on router 5 i will advertise also after pgp 3. okay so let's try now now it's working from router 5 to isp let's try the way back from isp router 205 1.5 for example it's okay 2.5 3.5 all right so what you have to do is you have only to advertise these uh links into bgp then it will be working okay and of course you have to not forget to to do on router 3 and router 4 for the neighbor 5.5.5.5 to do a next hop self okay we go to this do the number five make the change needed so that the isp router this router can reach the network 10.0.1 and then the 0.2 via r4 so it has to go from here to reach 10 to 0.1 and 10 to 0.2 and then we'll go to and to to reach 10 to 0.3 it has to go to router 3. so brief if you isp wants to reach let's support that this is a web server over here or whatever so in order to reach 10.0.1 and then the 0.2 it should take a router 4 and if wanted to reach 10 to 0.3 it should take router 3. okay and they said hint is metric so we have to use the attribute metric now this will have to be done on router 3 and router 4. so i go to router 3 [Music] and another three and here i have to say access list one permit tend to 0.1.0 so i'm classifying the ip address now and then i will create and access this two for this ip address then over here i will have to create a route map mat i'll call it permit 10 and i will say match ip address the access list one and set the metric we have to put the metric for now we are matching uh one which is 10.0.1 and 10 to 0.2 so we have to put the metric high because we don't want this to go through router 3 so we have to put metric 100 then i have to say exit then i will create another sequence for draw for route map 20 and then i will say match ip address now 2 which is this ip address at this network then the 0.3 and here i have to say set metric [Music] 50 so we make it lower so it takes this way and then we have to create finally uh route map map the permit sequence number 13 and that's will will keep it empty doesn't mean that it match anything so if we just check what we have configured show route map so we can see here that the sql stand match access list 1 and give metric 100 secrets 20 and match access list 2 and give metric for 50 and then sequence 30 it match anything so this is for for these links for example which are here all right now we have to apply the route map so i have to go to router bgp 3 and neighbor 192.168.13.1 which is isp and here i have to say route map and we name the route map matte and it should be the way out okay so this is on router 3. so if i do show ipvp now yeah we don't see anything on this router of course but if i go to isp uh you can see that we have of course this uh something we have to know about i bgp that we have always to clear the process take effect so as you can see now everything is going via router four and the reason why is because router for the metric is zero so we have to do the same job what we did on the other four as well so i have to go to router four now from here i have to create again access list 1 permit 10 to 0.1.0 accesses one permit to the zero and then axis list 2 3.0 and now i create a route map i would name it also mad you can name it anything you want but i just uh yeah because we're doing metric now attribute and here i have to say match ip address one and here i have to set the metric lower because the lower the better because we need these two ip address to these two to go from from router four so set metric of 50 then exit then i create sequence number 20 match ip address two and then set metric to 100 so this mean to reach this network you should yeah it gives a 100 while the router 2 gives 50 so it would choose router 2. and then finally 30 which match everything and now i have to go to router bgp three and i have to say neighbor two one system to 14.1 route map met and the way out clear ipbgp star okay so now let's have a look on isp okay if you can see here what's happening i think it's not so i'm checking here going to router 3 going to router 3 i'm going to write this there's show ipbgp summary 5pbgp okay now it's uh it's better okay so what we can see now is 10.0.1 is going via router 4 and that's what is needed and then the zero the two is going vr out to four because the metric is 50 of course then then the zero the three is going pr router three so this is the our object here they said make the chain need this so the isp can reach the network tend to do that one antenna due to router four which is here 10 to 0.1 then 0 the 2 router 4 which is correct and then 10 to 0 to 3 vr out of 3 10 to 0 to 3 this one here you can see the best vr outer street so we have we have uh accomplished the the mesh the mission uh to be sure you can just do trace route for example trace 100.1.5 and this is going to router 4 going down router 4. if you do tend to 0.2 2.5 also it's going to be a router 4 okay that's good then if we do that 3.5 that is going to router 3. all right excellent now make the change needed so that r5 carries the isp router by taking the pass via router 4. so this router router 5 if you want to reach this network here on isp it should take the personal router for so let's check now what pass is taking at the moment so if i do show ipvgp at the moment we can see here that it's taking uh the router's tree the password three so what we have to do we have to make it to go for router four and they give us a hint is you have to use local reference attribute so again i go to routers 3 and router 4 which is where we have to do the the change i create an access list let me check what was the number i used for axis list one two i'll create three access list three permit 1.1.1 1.1.1.000.255. now uh local preference the higher is better the metric the lower is better so you have to remember those now uh i create access list i have to create a route map i will name it local parents local preference permit 10 match ip address 1 and set local preference so we said the higher is better so we have to make it lower so i will put it 50 for example local preferences 50 and then i will go to router pgp3 neighbor so now you you will see that i would doing the neighbor without isp and not with router 4 5 but i would do with the way in so neighbor 192.168.13.1 route map local preference the way in clear ipdp star so now i have to go to router 4 and make local preference higher i have to create first act to show access list so one two i create access this three permit 1.1.1.0 zero zero zero two five five i'll create route map local preference also permit then match ip address so you can put my ip address three or oh match ip address one i put it here is wrong so uh let me correct for the router three router bgp route map local preference now route map local preference and it was permit then now match ip address 1 and i have to put match ip address 3. let's check now the roadmap [Applause] [Music] um we have to check show route map um [Music] local preference this is what i want to work on so route mat logo preference sequence 10 match ip address okay that's correct three but then we have to do route map local preference permit 20 and that's it so if i do now show route map local preference yes much better so now we are matching access this three and we are setting a local reference to 50 then we create a sequence number 20 which match which match anything so let me go back here i have to do clear ipvp star and let me go back to router four so router four i was doing saying match ip address three and now set metric at set the local preference to 200 exit then route map local preference permit 20 and then that's it so if i will show route map locker preference to show route map local preference so we are matching access this tree and we are setting preferred local preference to 200 then we are matching anything that's good so now i have to go to router bgp 3 and i'll say neighbor 192.168.14.1 and then route map local preference and now the way should be end now clear ippgp star so yeah it's it's all about logic so now let's go to router 5 show ipbp let's wait a little bit show our pbgp summary okay should be now up so ipbgp so now as you can see here that the router 5 has chosen has chosen to go to router 4 in order to reach the isp network because local preference is set to 200 okay so this is what we need to to see now someone would ask what if the network over here will go down what would happen so let's first do trace route to one to 1.1 to be sure so as you can see it's going to router 4. okay now if uh let's say the link goes down over here so for example if i do interface fast internet zero over one which is this here interface passes your net interface here and then make shot so uh what would happen what would happen in this case am i still able to ping 1.1.1.1 so let's try and yes you are able to ping it if i do trace route now 1.1.1.1 so what you can see here is going from this side to router 3 and then going down to router 4 and then going back to isp and the reason why if i go to router 3 and i do show ipbgp is because also local preference is shown as 200 okay uh now on if you do show ippgp you can see that it's still pointing to two four but as you can see on threshold it goes to router 3 so don't worry about that so let me bring up the interface now pick it back up and uh now do trash out to ensure that everything is working as requested by that scenario we already did it so this is all about the bgp and for ccnp level i hope you enjoyed this video

Channel: MAICT Consult

Views: 312

Keywords: what is cisco bgp, cisco bgp, cisco bgp configuration, cisco bgp local preference, cisco bgp router, cisco bgp path selection, cisco bgp commands, cisco bgp timers, cisco bgp troubleshooting, cisco bgp attributes, cisco bgp configuration guide, cisco bgp bfd, cisco bgp prepend, cisco bgp weight, cisco bgp community, cisco bgp commands cheat sheet, cisco bgp graceful restart, cisco bgp local preference higher or lower, cisco bgp router id, Maher Haddad, My Network Training

Id: xWwzSvp3gr0

Length: 35min 44sec (2144 seconds)

Published: Fri Jun 04 2021