603 weight using routemaps LAB

[Music] in this video we'll continue our lab relating to weight attribute so if you remember in our previous video we have configured some of the basic ibgp and ebgp configurations and then we change the next top behavior on the router 2 pointing towards router 3 by using next top self command and then we have verified that by default router 20 network or 30 network is getting advertised on router 1 via one path with only one as hops whereas it is also revised from other path which is 600 700 and i and by default it is going to use this as a best route because of least autonomous system path now and then what we did we applied some weight on the router 1 pointing towards router 4 some weight of 40 000 which we applied and once we do it once we did that now the router one is going to use this path via router 4 as the best route so let me just quickly show you the configurations because in this lab anyway we are going to continue with the weight but we are going to use some low backs also so quickly i'll give you some idea what we did here so i got all my configurations here if i give assurance pipe symbol section bgp and on the router 1 i have applied a weight of 40 000 here now once i applied that weight this is something what i did in our previous lap previous video so it's a continuation to that and if i verify show ipbgp 20. network and by default to reach this 20 network it is learning the route from 4.4.4.1 with two as hops that is router 4 with one airsoft and the default best route will be via 4.4.4 and if i try to trace to a 211 or thirty one one one it's going via router four then going to after three and out of one okay so now but the thing is if you remember in our previous lab when we applied the weight on router one pointing towards outer 4 the weight is applied for each and every route now each and every out coming from router 4 will be automatically applied the weight that's what happening here now all the routes learn from router 4 all the routes will be applied at a weight of 40 000 now you can come across a scenario where you have two multiple exit paths and by default maybe this is your best route and but what we can do is we can apply some weight on this side to make this weight higher than the weight here the default is zero now when you apply the weight of 1000 it's going to prefer this rule but in some cases you may want some of the traffic let's say on the router 2 or you have some routes let's say 10 dot network you have 20 network and you have 30 dot network and 40 dot network in some scenarios you may want your router to reach to reach the specific networks or this specific network should use of this route should exit wired of this route and all the remaining networks should use this route so this is what we can do by using route maps in bgp attribute now this is something what we will be doing in this lap what we will do is we will try to ensure we'll create some low backs here on the raptor too i got a pre-confirmed loopbacks so what i'm going to do is i'm going to continue with the same lab what i did the only thing is i'm going to remove the weight whatever i have applied in my previous lab if you just try to verify the weight which we applied i'm going to remove that so once i remove that weight automatically and if i give show clear ipvgp star soft command it's going to remove the weight and all the routes learns from both the side with the default values and by default the best proof will be yr after 2 this is the default best route and then i'm going to revise my low back interfaces here so my requirement is here the weight attribute using some route maps so what i'm going to do is i'm going to add some of the loopbacks on router 2 let's say there are four low backs which i am going to create and my requirements to ensure that by default to reach these specific loopbacks here like in our scenario anything going to router 2 this will be the best route because of less autonomous system paths now what i want to do is i want to ensure that to reach some specific routes let's say there are two low backs to reach these two low backs it has to go via this route this should be the best rule and to reach all the remaining low backs remaining low backs it should go via this route so which means i'm going to share the load to reach these specific destinations i want to use this link or this link and for the remaining networks should use this link so for only those two low backs i want to use this link so in that case we can also use weight but you need to apply the weight only for those two networks now that will be our requirement here now to apply this weight only for those two networks we need to create an acl which is going to match those two networks and then we need to configure a route map in that route map we have to define this acl and then we have to say set weight whatever the weight you want to apply so when i say apply the weight of 40 000 now the weight is going to apply only for the networks whatever we define in the acl and then finally we need to apply to router 4 towards out of 4 on the router 1 we need to say neighbor whatever the ip address of the router for and then we are going to say route map and the name of the route map whatever i use let's say cci and then we have to apply in so the direction anyway i'll explain so now the weight attribute can also be used along with route maps but if you want to match or apply a specific metric only to specific routes then it's it's really required to you to match the networks in the acl and use route maps and and apply the weight under the route map now in our previous lap the previous video which we discussed we didn't use any route map we just applied on the rafter 4 which means it will automatically apply for all the routes so that is something that's the basic difference because in most of the cases we don't really want our metric to apply for each and every network so we want to apply only for specific routes so that's what we are going to do here so the first step in our lab so i'm going to continue with my the same lap continue with your previous lab without removing anything just remove the weight attribute so when you remove the weight attribute on the router one it's going to use the default paths and then i'm going to clear the bgp and then i'm going to authorize those four loopback interfaces assuming that i have some couple of networks on the router two and i want to ensure that for to reach one of the two networks uh any two networks you should use uh route wire router four and for all the remaining networks it should use via router 2. so that anyway we'll see that next first let us quickly do this configuration i'm going to use loopbacks on the router 2. so just assuming that i got some networks so as per our default topology i have all my loopbacks pre-configured here only the thing i need to do is i need to advertise them in my bgp so 12.000 with a mask of two five five two five five two five five zero i'm using the mass slash 24 subnet mass so advertising all the interfaces and i want to verify whether these routes are coming into my bgp table or not you can verify the logo router itself and also you can verify them on the router one if i give show ipbgp now i should see the routes it will take some time okay now we can see the routes are coming here now to build our network 12.00 the first low back second low back third low back and the fourth low back and if you try to observe the best route the best route is y router 2 that is 1.101.2 now this is our best route so this is our diagram here now as per our diagram as per our default bgp policy now the root wire router 4 is considered the best route this is the best route now it is best route because of just one as hop that is 601 okay now what is my requirement here now my requirement is to ensure that and you can see the same table here by default router 1 is going to prefer via 1.1.1.2 to reach any of the 12 dot prefixes and even if you want you can verify your routing table as well so i'm just taking any network just to understand how the things are going to work if i try to trace it's going to use the same direct route if you want even you can verify your routing table all are going via 1.1.1.2 because of less asops now i have a requirement here now the task here is let's say your requirement is to ensure that make sure that only the loopback 12.000 and 1.0 should prefer wire out of four and whereas all the remaining networks should use the default route that is wire router 2. now my requirement here is just to ensure that to reach from router one to reach only the first two low backs let's say 12.0.0.0 is the first low back and 12.0.1.0 so to reach these two low backs it should go wire out of 4. it means router 4 should be my preferred path and for all the remaining networks remaining in the sense it includes the remaining two loopbacks it also includes your 20 door network a 30 dollar network anything going towards router 2 or wire after two all the remaining should use the default best route whichever is wire out of two the default is wire outer two as of now everyone is going for router two because of less as hops now we want to ensure that only to reach these two these two networks we should go wire out of four now in this case we need to match these two networks in your acl so that will be our first step now what i'm going to do is to make this possible i'm going to create an access list which is going to match it can be any number so i'll directly write the statements here in my program here i'll go to router 1 and then i will say the first thing i need to match those networks now to match these networks either you can use acls or prefix list now if you remember we did these basic things how to use route maps in our route filtering videos so so by this time you should be good with using this access list and route map statements so i'm going to say permit i'm not going to deny them i'm simply defining the permit statement with slash 24 separate mask so i'm going to say anything starting with 12.000 network and anything starting with 12.0.1.network or representing in the form of acl12 and then i'm going to say route map some name let's say cci or ccnp any name you can use just permit 10 and i'm going to say match ip address what is our ip address acl number is 12 i'm going to say match those two networks whatever i have defined in my acl 12 and then i'm going to say set weight when it says set weight it is going to be applied only to the networks whatever we have defined in the acl 12 and i'm going to give some 4 000 2000 any number you can give anything above zero and then you have to give a blank rotmap statement with permit 20 so ensuring that all the remaining routes should use the default values so if i am not defining anything which means all the remaining routes will be included in that and if i don't use any set command means automatically it's going to use the default values now the last step applying this so now i need to go to router 1 pointing towards router two because i want to prefer the wire router force so i need to apply on the router one so router one should exit to these two low backs by router four so i'm going to say out of bgp 500 now i'm going to send neighbor 4.4.4.1 and instead of applying the weight we are not applying the weight here we simply represent a route map and whatever the route map we created here if you remember the name we created ccnp and then we got two directions but for the weight we are going to use only one direction that is in when we say in so if you try out so it will not work because by default weight for out direction is not supported it only supports in so i'm going to say in here i'll explain you what is in what is out in short before that let me just quickly verify these things before i explain you again the directions as well say that you can use clear ippgp or clear ippgp star soft command now if i verify my bgp table show ipbgp and i want to just see only the 12 dot networks anyway you can see here this 12. network 0 0 0 the best part is wire router 4 that is 4.4.4.1 and the reason it's preferring this route because of the weight what we have applied and that weight is only applied for 12.00 and 12.01.0 network but if you try to see the other loopbacks the weight is not applied which means if i verify my routing table now these two networks goes via fodder for 4.1 that is our rafter four and all the remaining remaining means your remaining two loop backs and thirty dot network or twenty dot network all go via the default password now this way we can manipulate the best path for only specific routes and when you when you think about adding only for specific destinations then you need to add those statements in a specific acl and then you have to use rot maps and then you can apply some weight or local preference anything inside that route map and we can apply to that specific neighbor now this is the way we generally configure if you want if you want the weight to apply for specific routes okay so next thing i just missed this part a little bit the attribute the weight attribute is local to the router which we already discussed and it's not going to exchange weight information between the routers so therefore it is going only affect you on inbound rot map so it's going to work only on the inbound now there are a few few things we need to understand regarding understanding the in and out so let me quickly explain you regarding this

Channel: Sikandar Shaik

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Keywords: ccna, noa, ccna videos, ccnp, noa videos, cisco, ccie, subnetting, ccna security, bgp, ospf, firewall, ccna subnetting, ipv6, bgp videos, stp, ccna vdieos, ccna free video, ccie certification, ios, iou, virtual, eigrp, cisco virtual lab, iosv, asav, gns3, routing, noa vdieos, noa solutions, zone based firewall, zone pair, zbf, flsm, cisco firewall, cisco security, cisco certifications, wan, ip addressing, netmetric, vlsm, eigrp configuration, vlan, ccna, noa, ccna videos, ccnp, noa videos, cisco

Id: BGvYFNgtzTg

Length: 17min 0sec (1020 seconds)

Published: Sat Aug 08 2020