1 00:00:20,800 --> 00:00:26,800 This flock is a continuation of a previous blog discussing administrative distance or the believability 2 00:00:27,130 --> 00:00:29,270 of a routing protocol. 3 00:00:29,380 --> 00:00:36,830 In this example we've got four routers Rato one Rodda to write history and write a full Rodda to in 4 00:00:36,840 --> 00:00:38,260 the apology. 5 00:00:38,260 --> 00:00:44,800 He's only running away if we can see that by using the show IP protocols command. 6 00:00:44,800 --> 00:00:55,510 It has a relationship with both rodder one and wrote a full rodders three in the apology he's running 7 00:00:55,620 --> 00:01:02,960 up and GOP now in the real world you typically don't enable a whole bunch of writing protocols on your 8 00:01:03,030 --> 00:01:08,180 is we doing it here to explain that Mr. of distances. 9 00:01:08,260 --> 00:01:17,190 So show IP protocol and Rotto one rat of one is running rip your GOP as well as OSPF Rotto for he's 10 00:01:17,230 --> 00:01:18,290 doing the same. 11 00:01:18,530 --> 00:01:24,160 So on route of one show IP route the route of interest in this typologies could ripple fall. 12 00:01:24,240 --> 00:01:26,690 That's a loop back on Route 4. 13 00:01:26,800 --> 00:01:32,770 We can see in the writing table of Rato one that the rumped appears in the writing table and the protocol 14 00:01:32,770 --> 00:01:35,310 selected was GOP. 15 00:01:35,320 --> 00:01:40,580 That's because the GOP has an administrative distance of 90 which we can see here. 16 00:01:40,990 --> 00:01:44,320 SPF has an image of distance of 110. 17 00:01:44,320 --> 00:01:52,380 The loopback of Route 2 has been learnt via OSPF because we are not running the GOP on a t. 18 00:01:52,810 --> 00:01:57,880 The lower the administrative distance the more believable the routing protocol. 19 00:01:57,880 --> 00:02:06,250 So this ROFFT was selected because your job has a lower admin distance show IP OSPF database shows us 20 00:02:06,250 --> 00:02:13,900 that the route is available in the OSPF database but the GOP was selected because it has the lowest 21 00:02:14,300 --> 00:02:16,220 administer of distance. 22 00:02:16,420 --> 00:02:24,220 So at the moment show Bruhn section GOP shows us that the GOP is enabled on right of one. 23 00:02:24,250 --> 00:02:31,420 So if we remove the GOP from rodded one and then look at the routing table what you'll notice is that 24 00:02:31,420 --> 00:02:38,410 the rot has been added from OSPF the next hop is via a 10 1 1 2. 25 00:02:38,530 --> 00:02:48,360 If we scroll up previously the next top was tendered one to 1 to 2 which is routed three but because 26 00:02:48,440 --> 00:02:56,790 my job is no longer running on Route 1 The route is now available via Route 2 and was lent through OSPF 27 00:02:58,170 --> 00:03:00,850 So as an example if we trace to that route. 28 00:03:00,850 --> 00:03:04,580 Now notice that it goes via rodded too. 29 00:03:04,930 --> 00:03:14,740 We are still running up on this router so is running a rotas 3 router 1 and a full but the route is 30 00:03:14,740 --> 00:03:23,160 not selected for quadruple for because a rep has a higher administer of distance when compared to P.F. 31 00:03:23,830 --> 00:03:30,140 So the loopback of router 3 is advertised via up to one. 32 00:03:30,430 --> 00:03:36,640 And because I was P.F. is not advertising that route the route is put into the writing table but because 33 00:03:36,680 --> 00:03:42,640 I always be advertising this route and it has a lower administered distance when compared to up the 34 00:03:42,650 --> 00:03:49,670 OSPF route is used not route so to confirm that and try and prove it to you. 35 00:03:49,900 --> 00:03:57,430 I'm going to remove job P from router 3 serratus 3 36 00:04:00,080 --> 00:04:01,900 is running up. 37 00:04:02,070 --> 00:04:10,020 It's not running IGMP rope is the only running protocol running on road 3 to 1. 38 00:04:10,050 --> 00:04:17,790 We can see the loopback of router 3 learnt via a rep but we don't see the loop back of router for because 39 00:04:17,820 --> 00:04:28,840 OSPF takes precedence so let's remove who is P.F. show IP rot we haven't learnt about the route through 40 00:04:29,080 --> 00:04:29,820 yet. 41 00:04:30,130 --> 00:04:32,830 So let's do some investigation to make sure things are working. 42 00:04:32,830 --> 00:04:35,500 Show IP wrapped on rotatory. 43 00:04:35,770 --> 00:04:40,840 Notice the rot has been learnt via a rope on Rotto one. 44 00:04:40,960 --> 00:04:43,930 It's now available. 45 00:04:43,980 --> 00:04:45,600 I was a bit impatient. 46 00:04:45,900 --> 00:04:56,440 Takes longer to advertise routes so now paying quadruple for trace could ripple for it's going via a 47 00:04:56,440 --> 00:04:57,850 router 3. 48 00:04:57,940 --> 00:05:06,960 And that's because the only routing protocol that's running on Route 1 is reep So the writing table 49 00:05:07,050 --> 00:05:16,020 is populated with broths the reader won't be able to ping the Lubeck of Ratatouille because Gruppe is 50 00:05:16,020 --> 00:05:18,380 not running on Rodda too. 51 00:05:18,630 --> 00:05:23,130 So we need to enable replan right to feed one for connectivity in the network. 52 00:05:23,430 --> 00:05:24,840 But for now I'm not going to do that. 53 00:05:24,870 --> 00:05:28,280 I want to prove to you that OSPF takes precedence. 54 00:05:28,320 --> 00:05:33,740 So notice the wraparound isn't the writing table with an administrative distance of 120 counties to 55 00:05:34,250 --> 00:05:37,400 it's available via tendered one to two to two. 56 00:05:37,590 --> 00:05:45,150 It's been in the writing table for 19 seconds and it's available via a gigabit 0 1 that's lets enable 57 00:05:45,720 --> 00:05:58,010 OSPF network and all the naval P.F. on all interfaces show IP OSPF neighbor. 58 00:05:58,200 --> 00:06:03,030 We have a neighbor relationship with reality show IP route. 59 00:06:03,300 --> 00:06:12,780 Notice the writing table has been updated always takes precedence over ripe so the path you use to get 60 00:06:12,790 --> 00:06:16,300 to quadruple four is via router too. 61 00:06:16,840 --> 00:06:20,290 If we enable the GOP on this Rodda 62 00:06:24,440 --> 00:06:33,140 traffic will still go via rodded too because we need to enable the GOP on Radio 3 so let's do that Rodda 63 00:06:33,310 --> 00:06:40,630 you know job P enable your job and all interface's neighbor relationship has been established. 64 00:06:40,630 --> 00:06:42,280 So show I.P your job. 65 00:06:42,320 --> 00:06:49,760 Neighbor neighbor relationship is available show IP rocked the GOP Raat has now been put into the writing 66 00:06:49,760 --> 00:06:50,680 table. 67 00:06:50,930 --> 00:06:58,660 And if we trace that loop back it's going via router three site administer distances work as follows. 68 00:06:58,760 --> 00:07:00,580 The lowest number wins. 69 00:07:00,590 --> 00:07:05,330 Different routing protocols have different administrative distances set by default. 70 00:07:05,330 --> 00:07:07,120 You can change them. 71 00:07:07,170 --> 00:07:18,740 Wrap is 120 SPF is 110 hijo internal Roths is 90 but I could as an example add a route to the writing 72 00:07:18,740 --> 00:07:24,880 table steadily at a static route to force the traffic to go via rockety. 73 00:07:25,070 --> 00:07:31,640 Now when we look at the writing table notice the static route has replaced the GOP because a static 74 00:07:31,640 --> 00:07:36,320 route to a next top IP address has an admin distance of one. 75 00:07:36,440 --> 00:07:43,580 Is nothing more believable than you as in the router believes you more than it believes a algorithm 76 00:07:43,790 --> 00:07:51,170 such as your job is P.F. and thats because you know what you are doing and the rodded believe you more 77 00:07:51,170 --> 00:07:54,260 than the police or the rodders. 78 00:07:54,280 --> 00:08:01,950 So once again trace via wrote a TV show run popping clewed rot. 79 00:08:02,410 --> 00:08:12,140 We've got the static route forcing the traffic via roads to well remove the static ROFFT should not 80 00:08:12,180 --> 00:08:13,610 be dropped. 81 00:08:13,610 --> 00:08:15,530 Your job is the most believable now 82 00:08:18,500 --> 00:08:22,360 traffic is going via road history. 83 00:08:22,740 --> 00:08:24,210 Remove your choppy 84 00:08:27,670 --> 00:08:29,380 always be fraught takes precedence. 85 00:08:29,380 --> 00:08:40,160 Now traffic is going via router too so that is a demonstration of ministry of distance or the believability 86 00:08:40,160 --> 00:08:43,040 factor of a rant for the CCMA exam. 87 00:08:43,040 --> 00:08:46,630 You need to know admin distances in a separate video. 88 00:08:46,630 --> 00:08:49,180 I'll show you an example with BGP. 89 00:08:49,190 --> 00:08:54,820 Hope you've enjoyed the video please like it please subscribe to my YouTube channel. 90 00:08:54,830 --> 00:08:56,120 I wish you all the very best.