1 00:00:00,690 --> 00:00:03,960 REPORTER two In this example is an area border, rather. 2 00:00:04,050 --> 00:00:09,690 So we have to configure interfaces in both Area one and Area zero. 3 00:00:10,200 --> 00:00:13,380 Rotor three is also an area border router. 4 00:00:13,410 --> 00:00:18,660 It has an interface, an area zero as well as an interface in area two. 5 00:00:18,960 --> 00:00:23,940 We've been told to configure OSPF using interface commands. 6 00:00:25,640 --> 00:00:34,130 So on raw two three we have this interface which needs to be in Area two. 7 00:00:34,730 --> 00:00:42,110 This interface needs to be an Area zero and we'll configure the loopback interface in Area zero as well. 8 00:00:42,260 --> 00:00:46,280 So router OSPF one, that's all we need to do. 9 00:00:46,280 --> 00:00:55,580 Now, what we need to do in this example is go on to interfaces because we've been told to enable OSPF 10 00:00:55,640 --> 00:00:57,380 using interface commands. 11 00:00:58,730 --> 00:01:13,220 IP OSPF Process one area zero interface gigabit zero one IP OSPF Area zero interface gigabit zero zero. 12 00:01:13,310 --> 00:01:22,730 In this case, interface gigabit is zero zero is going to be in area two, actually not area one. 13 00:01:23,360 --> 00:01:26,540 So let's confirm that I did that right. 14 00:01:27,590 --> 00:01:31,550 This interface needs to be in Area Zero. 15 00:01:33,020 --> 00:01:37,220 This interface needs to be in area two. 16 00:01:37,310 --> 00:01:38,210 That's good. 17 00:01:38,540 --> 00:01:41,960 And this interface needs to be an area zero. 18 00:01:42,440 --> 00:01:43,820 We can confirm that. 19 00:01:43,820 --> 00:01:47,630 We've done that right by using the show IP Interface Command. 20 00:01:48,440 --> 00:01:55,670 In the real world you may want to use show IP OSPF interface brief packet tracer doesn't support that 21 00:01:55,670 --> 00:02:01,310 command, it only supports the detailed command rather than brief. 22 00:02:01,850 --> 00:02:11,060 We can see that the loopback is in area zero gigabit is zero one, is in area zero and gigabit is zero 23 00:02:11,060 --> 00:02:11,900 zero. 24 00:02:12,650 --> 00:02:15,140 Is now in area two. 25 00:02:15,830 --> 00:02:17,150 So that looks good. 26 00:02:17,150 --> 00:02:19,340 Show ip ospf neighbor. 27 00:02:20,090 --> 00:02:26,150 We have a neighbor relationship established rather to show IP route. 28 00:02:26,330 --> 00:02:31,370 We see both intra area OSPF routes. 29 00:02:32,130 --> 00:02:36,480 As well as into area OSPF routes. 30 00:02:36,780 --> 00:02:43,680 This route came from area one, whereas this route originated in area zero. 31 00:02:44,310 --> 00:02:44,880 Yes. 32 00:02:44,880 --> 00:02:48,990 A another inter area ospf route. 33 00:02:49,140 --> 00:02:50,880 So ping ten 111. 34 00:02:52,270 --> 00:02:52,960 That works. 35 00:02:52,960 --> 00:02:55,080 Ping 1.1.1.1. 36 00:02:55,090 --> 00:02:56,500 That also works. 37 00:02:56,890 --> 00:03:03,700 So we have connectivity now between router three and. 38 00:03:04,990 --> 00:03:13,810 Root of two and root of one on router one show IP root we see an inter area root for the loopback of 39 00:03:13,810 --> 00:03:22,780 router three and we also see inter area roots for ten 1 to 0 as well as ten 130. 40 00:03:23,680 --> 00:03:25,780 So can we ping the loopback of router two? 41 00:03:25,810 --> 00:03:26,920 Yes, we can. 42 00:03:27,640 --> 00:03:28,870 What about router three? 43 00:03:28,900 --> 00:03:29,920 Yes, we can. 44 00:03:30,010 --> 00:03:30,820 What about ten? 45 00:03:30,820 --> 00:03:31,810 One, two, one. 46 00:03:31,840 --> 00:03:32,940 Yes, we can. 47 00:03:32,950 --> 00:03:33,310 Ten. 48 00:03:33,310 --> 00:03:34,390 One, two, two. 49 00:03:34,420 --> 00:03:35,440 Yes, we can. 50 00:03:36,450 --> 00:03:39,150 The network is working as expected. 51 00:03:39,330 --> 00:03:42,660 So the last router to configure is router four. 52 00:03:43,140 --> 00:03:45,030 That's a fairly easy one. 53 00:03:47,610 --> 00:03:53,040 On rather for we need to enable all interfaces with a single network command. 54 00:03:53,520 --> 00:03:58,710 So on right of for rather ospf one network. 55 00:03:59,340 --> 00:04:06,870 And we can simply do this to enable OSPF on all interfaces in area two. 56 00:04:07,800 --> 00:04:14,370 So what should happen is we should see a neighbor relationship established to router three. 57 00:04:14,730 --> 00:04:17,130 It may take it a while to form. 58 00:04:18,399 --> 00:04:21,730 In the meantime, we can check that OSPF is enabled. 59 00:04:22,420 --> 00:04:25,480 As you can see there, the relationship has just come up. 60 00:04:26,260 --> 00:04:28,860 But she has the output of show IP protocols. 61 00:04:28,870 --> 00:04:31,330 We running OSPF and process ID one. 62 00:04:31,600 --> 00:04:40,870 We have enabled OSPF on all interfaces using this command and all interfaces belong to area to show 63 00:04:40,870 --> 00:04:41,980 IP route. 64 00:04:42,550 --> 00:04:50,200 Here we see an interior route from area one into area routes from area zero. 65 00:04:51,070 --> 00:04:54,040 Area zero into area routes. 66 00:04:54,220 --> 00:05:02,410 There are no OSPF intra area routes because on router three, the loopback and this interface are in 67 00:05:02,410 --> 00:05:03,520 area zero. 68 00:05:03,670 --> 00:05:08,200 There are no other interfaces in area two on router three. 69 00:05:08,620 --> 00:05:12,070 So ping 1.1.1 that works. 70 00:05:12,070 --> 00:05:13,840 Can we trace to router one? 71 00:05:14,290 --> 00:05:18,220 Yes, we can ping the loopback of router two. 72 00:05:18,760 --> 00:05:19,690 That works. 73 00:05:19,690 --> 00:05:22,300 Loopback of router three that works. 74 00:05:23,170 --> 00:05:31,360 So after this point we've successfully configured OSPF on all our routers router foes OSPF database 75 00:05:31,690 --> 00:05:34,570 only shows information for area two. 76 00:05:35,080 --> 00:05:37,660 There are two routers in Area two. 77 00:05:37,840 --> 00:05:40,570 These are LSA Type one advertisements. 78 00:05:41,830 --> 00:05:49,120 There is one designated router in area two and that designated router is router three. 79 00:05:49,900 --> 00:05:51,940 These are LSA type three's. 80 00:05:52,330 --> 00:06:01,150 In other words, summary ALA says these networks originated in other areas and we can see that. 81 00:06:02,010 --> 00:06:07,470 Over here by looking at inter area in the routing table. 82 00:06:07,680 --> 00:06:12,240 So these routes came from a different area to area to. 83 00:06:14,830 --> 00:06:16,540 On Router three. 84 00:06:18,260 --> 00:06:29,090 Show IP OSPF database router three has interfaces in area zero as well as area two. 85 00:06:29,360 --> 00:06:37,340 So it sees two routers in area zero one designated router in area zero. 86 00:06:37,370 --> 00:06:39,890 Designated router is rather two. 87 00:06:40,880 --> 00:06:46,640 It sees summary losses, type three losses in Area zero. 88 00:06:46,790 --> 00:06:50,180 These networks originated from other areas. 89 00:06:50,660 --> 00:06:54,530 As an example, this network originated from Area one. 90 00:06:55,130 --> 00:06:57,800 This network originated from Area two. 91 00:06:59,030 --> 00:07:07,340 Router three also has interfaces in area two, so it sees two riders and Area two, one designated writer 92 00:07:07,340 --> 00:07:17,390 in Area two and these summary or LSA Type three networks in Area two routers in areas have the same 93 00:07:17,390 --> 00:07:18,440 database. 94 00:07:19,100 --> 00:07:24,290 So the database of router three and router four are the same four. 95 00:07:24,290 --> 00:07:30,590 Area two database for router two and router three are the same for area zero. 96 00:07:30,860 --> 00:07:34,910 Database for router one and router two are the same for area one. 97 00:07:35,030 --> 00:07:39,260 So going back to router one, show IP OSPF database. 98 00:07:41,340 --> 00:07:47,490 Rather one only has interfaces in area one, so we only see area one. 99 00:07:48,220 --> 00:07:52,360 Two roads in area one one designated rotor. 100 00:07:52,630 --> 00:07:55,750 These routes originated from other areas. 101 00:07:56,670 --> 00:07:59,310 Show IP route shows us that again. 102 00:07:59,850 --> 00:08:01,170 Notice this loopback. 103 00:08:01,200 --> 00:08:04,950 The loopback of router four is an entire area route. 104 00:08:05,850 --> 00:08:11,070 Originated in another area, but rather one can still ping that loopback. 105 00:08:11,460 --> 00:08:16,830 We've successfully configured this network with OSPF in multiple areas. 106 00:08:16,860 --> 00:08:18,070 How did you get on? 107 00:08:18,090 --> 00:08:20,400 Were you able to do this yourself?