2.3.11 Packet Tracer - Determine the DR and BDR

hi friends welcome to world in this video we are going to solve the packet tracer activity determine the dr and bdr before coming to this activity friends if you like to get any ccna version 7 online support or any other project support you can contact our team using our website link you will get from the description below and also if you like to get these type of technical videos in future consider subscribing and don't forget to enable that bell icon new to the subscribe button so that you will get notification message whenever we upload a new video back to the activity here we can see our addressing table and objectives in part one examine dr and bdr changing roles then in part two modify osp of priority and force elections scenario in this activity we will examine dr and vdr roles and watch the roles change when there is a change in the network we will then modify the priority to control the roles and force a new election finally we will verify our routers are filling the desired routes coming to the instructions part one examine dr and bdr changing rods step one wait until uh the amber ling lights turn green yeah we can see all the lights are in green now when you first open the file in pack tracer you may notice that the link lights for the switch are amber these link lights will stay amber for 50 seconds while the hdp protocol on the switch make sure that one of the routers is not another switch alternatively you can click fast forward time to bypass this process yes it was so in the beginning we have seen all these switches were in amber and now it's in green color coming to step 2 verify the current ospf neighbor states use the appropriate command on each router to examine the current dr and bdr if a rotor shows full bar dr other it means that the rotor is not a dr or a bdr and here itself they've shown the output for all these uh show command on each router's ra rb and rc here we can see that our a show ipospf neighbor and we can see this 192 168 31.33 it's a full bar dr that means this router rc then it's a 31.22 it's a full bar bdr it's your total rb and here we can see this router 192 168 31.11 that is this router ra is in dr other we have this question so which router is the dr yeah we have seen uh 192.168.31.33 is the dr that means this router rc then which router is the bdr here we can see bdr19216831 dot 22 uh rb rotor and what is the ospf state of router r a uh we can see etc 31.11 and it's a dr other just we will verify this in our topology using this show command show ip ospf neighbor so we'll go to ra enable show ip ospf neighbor and here we can see 192 168 31.22 it's a bdr and 31.33 it's a dr that means rc will be the designated router and rb will be the backup designated router now we will go to rb and we can give that same command enable show ip ospf neighbor we can see this is r a and this is rc and this ra is in dr other and 31.33 is in designated router you go to rc show ip ospf so bdr 31.22 also we have a 31.11 dr other step 3 turn on ip ospf adjacency debugging you can monitor the dr and bdr election process with the debug command on ra and rb enter the following command that is a debug ip ospf adj that is a ospf adjacency event so we have to give in both routers r a and rb we will go to our a here we can give a debug we have ip ospf here we can see adj ospf adjacency events ospf adjacency events debugging is on now we will go to rb debug ip isp of adj and ospf adjacency even so debugging is on step four disable the gigabit ethernet zero slash zero interface on rc okay use the shutdown command to disable the link between rc and the switch to cause arrows to change wait about 30 seconds for the dead timers to expire on r a and rb according to the debug output which router was elected dr and which router was elected bdr we can guess that right so according to this topology rc is the uh you know designated router and rb is the backup designated router so once this rc goes down this backup uh designated router becomes uh this um dc right and obviously ra become the backup designated router okay we will verify that we will go to this rc then to this interface g 0 slot 0 then we will shut down this interface okay here i will go to conf t then we will go to that interface that is g 0 0 once more i will verify that interface is correct and we will give shutdown command and we get some message here we can see neighbors 31.22 it's a detached or down okay okay so just we'll go to these routers rb okay let me come back to this rna okay that's fine actually we have to wait 20 to 30 seconds yeah sure we get some message in our a here we get some message let me check that you can see elect bdr19216831.22 and he become dr 192.168.31.22 okay so here we can see dr 192.168.31.22 that means rb become now designated router then the video is 192.168.31.11 that means ra become the bdr step five restore the gigabit ethernet zero star zero interface on rc re-enable the link between rc and the switch then wait for the new dr bdr elections to occur a dr and the bdr roles change explain okay we will check that just i will give a no showdown here no shutdown obviously not there won't be any change in dr and media rb will be the dr and ra will be the backup designated router sure one thing we have to keep in mind uh previously rc was the dr that is a designated router so now um we shut down and rb become d r and r a become bdr so once he be activated back he will not become the dr back so that is not happening in the ospf okay that's fine we will verify the dr and the bdr assignments using the show iep or spf neighbor command on a router rc so show iep ospf neighbor enable show ip ispf neighbor and here we can see 192.168.31.11 is the bdr uh that is ra and dr is 192.168.31.22 it's rb they're given a note if the show ip ospf neighbor command it does not return rb as the dr and ra as the bdr 10 of debugging on our a and rb with the and debug all command and retry steps four and five yeah it's working for us so we will go to step six disable the gigabit ethernet 0 0 interface on rb disable the link between rb and the switch to cause or rolls to change wait about 30 seconds for the hold down timers to expire on r a and rc then according to the debug output on ra which router was elected dr and which router was elected bdr we will go to this router rb and we will shut down this uh interface g 0 0 conf t sorry county interface g 0 slash 0 and we will shut down this interface and here we can see the messages so everything removed and they are electing the new dr and bdr so we will wait for 30 seconds then we will go to this ra and here we received these messages dr 192 168 31.11 and the bdr is 192 168 31.33 so now dr become this router r a correct 31.11 and the bdr is 31.33 uh this rotor rc coming to step seven restore the gigabit ethernet zero slash zero interface on rb re-enable the link between rb and the switch wait for the new dr bdr elections to occur i did dr and bdr roles change explain okay just will go to rb and we will give no shut command after activating this router rb uh there will not be any change in dr and bdr dr will be this r a and the bdr will be this rc we can verify that we will go to rb and we will verify it coming to rb okay and here we will give that command to show ip ospf sniper and we can see 192 168 31.11 still india that means ra and uh here we can see 192 168 31.33 it's in bdr that means this router rc use the show ip ospf interface command on router rc what is the status of a rotor rc now the status of this rotor rc we already verified uh it's in you know backup a designated router right uh we given the show command here in this rb show ipo spf neighbor and here we can see 192.168. 31.33 it's in bdr anyways we will give this a short command to show iep ospf interface in this router rc coming to this router rc show ipospf interface and here we can see the details internet address process id router id okay and here we can see state bdr backup designated router now step 8 10 of debugging enter the command and debug all on ra and rb to disable debugging okay we will give that command and debug all coming to our a and debug all now coming to party 2 modify ospf priority and force elections step one configure ospf priorities on each router to change the dr and the bdr i use the ip ospf priority command to configure the gigabit third zero snare port of each router with the following ispf interface priorities for ra we have to give it 200 for rb 100 and for rc1 this is the default priority and here they show uh this priority configuration for the order r a interface g 0 0 then i p o s p of priority 200 so we can do that we will go to our a conf t he will go to that interface g 0 0 and we have to give ip ospf priority 200 next we will go to rb conf t interface g 0 slash 0 and we will set ip ospf priority 100 okay right then coming to this rc conf t we will go to the interface g 0 slash 0 ip ospf priority one step two force an election by resetting the ospf process on the rotors starting with the rotor ra issue the clear ip ospf process on each router to reset the ospf process okay we will do that coming to our a and here we will give that command uh clear ip ospf process so just will give end and here we can give clear ip ospf process so reset all ospf processors yes now we will go to rb exit exit and here we will give a clear ip ospf process yes then we will go to rc end sorry clear ip ospf process yes coming to the last step step 3 verify dr and bdr elections were successful wait long enough for ospf to converge and for the dr bdr election to occur this should take a few minutes you can click fast forward time to speed up the process okay so just we can give fast forward and we can verify this at dr and media according to the output from the show ipo spf neighbor command on the routers which router is now dr and which router is now bdr the given a node if the routers do not elect the correct dr and the bdr after uh setting the isp of priorities try restarting packet tracer okay we will identify this so i will go to rc and let me give the show command show ip ospf neighbor and we can see 192 168 31.11 is the dr uh that means ra is the dr now okay and 192 168 31 31.22 31.22 that is rb rb is the bdr so it's correct okay that's great so in this packet tracer activity uh just to be learned about the dr and bdr and how they elected here we can see it's the completion status uh it shows hundred percent now dear friends if you get any doubt or if you like to give any suggestions please comment below or you can contact our team using our website and also if you like our video give a thumb and share with all your friends stay tuned and we will meet again with the next video thank you

Channel: Tech Acad

Views: 8,446

Keywords: CISCO, CISCO Certification, CCNAv7, CCNA Routing and Switching, CCNA, Routing and Switching, DR, OSPF, CISCO Router

Id: hI6zY--8oVg

Length: 21min 12sec (1272 seconds)

Published: Mon Aug 17 2020