1 00:00:19,400 --> 00:00:22,400 This Flug are you going to continue discussing it. 2 00:00:22,430 --> 00:00:27,520 Mr. distances and the believability of writing protocols. 3 00:00:28,060 --> 00:00:37,630 So on one show I wrote why in this apology is this loop back available in the writing table through 4 00:00:37,630 --> 00:00:38,780 BGP. 5 00:00:39,220 --> 00:00:41,570 And why not for this route. 6 00:00:41,590 --> 00:00:50,140 So this network to dot 2.0 too is available in the writing table and the ront has learnt a viable g.p 7 00:00:51,100 --> 00:00:54,370 this network has learnt of your job. 8 00:00:54,850 --> 00:00:59,640 So why is BGP used for the one network and not the other. 9 00:00:59,650 --> 00:01:03,460 The first thing you need to look at is look at this admin distance here. 10 00:01:03,550 --> 00:01:04,430 Its 20. 11 00:01:04,660 --> 00:01:08,150 So that BGP route has an administrative distance of 20. 12 00:01:08,310 --> 00:01:15,280 What are the administrative distances of BGP and what you must remember is that you have two versions 13 00:01:15,280 --> 00:01:26,030 of BGP BGP and IBG P E BGP has an admin distance of 20 BGP has an admin distance of 200. 14 00:01:26,350 --> 00:01:29,370 So show IP BGP summary. 15 00:01:29,620 --> 00:01:41,560 We have a neighbor relationship to router to as well as two routers three show IP BGP neighbor the relationship 16 00:01:41,950 --> 00:01:45,820 to Rodda to uses IE BGP. 17 00:01:45,960 --> 00:01:54,470 Notice the autonomous system number for oddities to view and scrolling down the neighbor 10 1 to 2 which 18 00:01:54,470 --> 00:02:01,640 is rotted 3 is using BGP router 3 is an autonomous system one. 19 00:02:01,800 --> 00:02:04,040 The relationship is established. 20 00:02:04,050 --> 00:02:07,710 Are we learning the routes through BGP. 21 00:02:07,710 --> 00:02:09,750 So show IP BGP. 22 00:02:09,750 --> 00:02:16,760 Yes we are learning both the loopback of router 2 as well as the loopback of router 3 through BGP. 23 00:02:17,040 --> 00:02:24,210 So BGP has both routes in the BGP routing table but this route is not being put into the IP writing 24 00:02:24,210 --> 00:02:31,530 table and we can see that because of this or it says a rope failure the rope is the wrong information 25 00:02:31,530 --> 00:02:35,720 base which from a CCMA point of view is the writing table. 26 00:02:36,060 --> 00:02:45,210 So this route is not put into the periodic table by BGP and that's because a better route is available 27 00:02:45,600 --> 00:02:47,320 through the GOP. 28 00:02:47,430 --> 00:02:55,170 So 3 3 3 3 and 4 forward and forward for a post not put into the periodic table. 29 00:02:55,260 --> 00:02:56,950 Show IP BGP. 30 00:02:57,240 --> 00:03:00,210 We're not learning quadruple for three BGP. 31 00:03:00,330 --> 00:03:06,000 We are all learning about this route but because of the failure it's not put into the writing table 32 00:03:06,360 --> 00:03:07,810 notice here. 33 00:03:08,190 --> 00:03:15,220 The rot was learned through BGP and the reason why this route is not put into the writing table is because 34 00:03:15,540 --> 00:03:20,570 your job P has a lower administrative distance. 35 00:03:20,710 --> 00:03:22,730 Then I BGP. 36 00:03:22,780 --> 00:03:27,320 So to prove that let's remove your GOP from Rodda one. 37 00:03:27,400 --> 00:03:34,020 So rather no Rodda your GOP one show IP rot. 38 00:03:34,120 --> 00:03:39,560 Notice the rot is now available through BGP had been. 39 00:03:39,560 --> 00:03:41,950 Distance is 200. 40 00:03:41,950 --> 00:03:50,100 So remember IBG has an industrial distance of 200 e BGP has an admin distance of 20. 41 00:03:50,170 --> 00:04:02,320 If we shut the neighbor relationship down neighbor 10 10:01 1 to shut down what we should see is that 42 00:04:02,380 --> 00:04:05,230 the rot is replaced by another writing protocol. 43 00:04:05,230 --> 00:04:06,960 In this case it's always P.F.. 44 00:04:07,150 --> 00:04:11,770 So I'm running OSPF and wrote one and wrote it to you and wrote one has learnt about that loop back 45 00:04:11,890 --> 00:04:20,560 through a whisper of previously because the rot was learnt through IBG the BGP rot took precedence. 46 00:04:20,680 --> 00:04:28,280 But now because we've shut down the neighbor relationship OSPF is able to add the rot to the writing 47 00:04:28,280 --> 00:04:29,030 table. 48 00:04:29,180 --> 00:04:35,850 So no neighbor 10:01 want to shut down when that relationship comes up 49 00:04:38,590 --> 00:04:40,340 which it has. 50 00:04:40,580 --> 00:04:48,500 We should see the rot replaced by a BGP rot and we can on this example reap took a long time to converge. 51 00:04:48,620 --> 00:04:56,580 But notice Ripp has been used as the writing protocol to get to this loopback rather than BGP repairs 52 00:04:56,700 --> 00:05:03,020 and Edmon distance of 120 BGP has an admin distance of 200 Ripp is more believable. 53 00:05:03,020 --> 00:05:13,370 So if we removed wrap from the router what we should see is the rot is now available through BGP. 54 00:05:13,370 --> 00:05:19,770 So in summary I BGP has an admin distance of 200 RP has an admin distance of 120. 55 00:05:19,850 --> 00:05:27,980 ISIS has an admin distance of 115 always P.F. has an admin distance of 110 GOP internal Rantz have an 56 00:05:27,980 --> 00:05:35,570 admin distance of 90 static routes to next top addresses have a admen distance of one static route to 57 00:05:35,570 --> 00:05:38,820 directly connected interface has an admin distance of zero. 58 00:05:38,900 --> 00:05:42,790 The lower the number the more believable the running protocol. 59 00:05:43,070 --> 00:05:53,640 Remember with BGP we have both BGP and IBG P E BGP admin distances 20 BGP admin distances 200. 60 00:05:53,660 --> 00:05:56,410 Make sure you know you administrative distances. 61 00:05:56,480 --> 00:05:57,980 Completes this Flug. 62 00:05:58,220 --> 00:06:00,410 If you've enjoyed the video please like it. 63 00:06:00,410 --> 00:06:04,770 And very importantly please subscribe to my YouTube channel. 64 00:06:04,910 --> 00:06:06,380 I wish you all the very best.