1 00:00:01,260 --> 00:00:09,330 En route a to show ip ospf neighbor notice the neighbor relationship has changed to use the loopback 2 00:00:09,330 --> 00:00:11,190 address of quadruple one. 3 00:00:12,830 --> 00:00:18,830 So let's enable OSPF on router three to ensure full connectivity between all subnets. 4 00:00:21,500 --> 00:00:26,870 Show IP interface brief will allow me to see the interfaces configured on this router and you can see 5 00:00:26,870 --> 00:00:33,860 forced ethernet zero and the two serial interfaces serial 1/0 and serial 1/1 have IP addresses enabled 6 00:00:33,860 --> 00:00:35,960 on them and the interfaces are up. 7 00:00:36,230 --> 00:00:40,130 Let's configure a loopback for this router interface loopback zero. 8 00:00:41,230 --> 00:00:42,250 IP address. 9 00:00:44,230 --> 00:00:45,410 And they just make it quadruple. 10 00:00:45,410 --> 00:00:45,980 Three. 11 00:00:48,000 --> 00:00:54,180 Topping the command show, IP protocols will allow me to see that there are no protocols enabled on 12 00:00:54,180 --> 00:00:54,930 this writer. 13 00:00:55,200 --> 00:01:01,020 Once again, show IP protocols displays no output as no writing protocols are enabled. 14 00:01:01,710 --> 00:01:04,739 Going into global config mode rather. 15 00:01:05,710 --> 00:01:06,610 OSPF. 16 00:01:07,600 --> 00:01:09,280 And I could use process ID three. 17 00:01:09,280 --> 00:01:17,020 In this case, I'm using different process IDs just to prove the point that the process IDs are local 18 00:01:17,020 --> 00:01:21,790 to the Rada and do not have to be the same across all routers in the real world. 19 00:01:21,790 --> 00:01:27,850 It would make more sense to use the same process number on all of your routers if possible. 20 00:01:28,210 --> 00:01:31,270 In other words, standardize on the process ID. 21 00:01:31,690 --> 00:01:34,840 In this case, I could type the command network. 22 00:01:35,600 --> 00:01:37,610 Ten .1.3.0. 23 00:01:39,380 --> 00:01:41,840 And put in the wild card, moss. 24 00:01:43,110 --> 00:01:43,980 As follows. 25 00:01:44,280 --> 00:01:50,070 In other words, use the exact inverse of the network mask. 26 00:01:50,220 --> 00:01:55,560 And as you can see here, a neighbor relationship was established between router three and router two. 27 00:01:56,040 --> 00:02:04,470 I could use a command to show IP OSPF neighbors to see that that neighbor relationship has established. 28 00:02:05,130 --> 00:02:09,810 I could then enable OSPF on serial one one. 29 00:02:09,810 --> 00:02:13,320 So network ten .1.5.0. 30 00:02:14,330 --> 00:02:17,870 With the wild card mosque, putting it into Area Zero. 31 00:02:18,470 --> 00:02:22,490 And now a neighbor relationship has been established with router one. 32 00:02:22,490 --> 00:02:29,480 So do show ip ospf neighbors shows me that on router three I have two neighbor relationships with router 33 00:02:29,480 --> 00:02:35,030 one and with router two topping that come on network ten 140. 34 00:02:35,910 --> 00:02:41,880 Will enable OSPF on the first Ethernet zero zero interface. 35 00:02:42,060 --> 00:02:50,280 So now typing the command do show IP OSPF interface allows me to see that OSPF is enabled on the first 36 00:02:50,280 --> 00:02:52,080 Ethernet zero zero interface. 37 00:02:53,270 --> 00:03:02,930 The serial one one interface, 010 interface, but not on the loopback interface, even though OSPF 38 00:03:02,930 --> 00:03:05,060 is not enabled in the loopback interface. 39 00:03:05,970 --> 00:03:09,990 The Rada ID is set to the loopback IP address. 40 00:03:10,290 --> 00:03:15,630 So lastly, I should do this network quadruple three exact match. 41 00:03:16,990 --> 00:03:18,010 Area zero. 42 00:03:18,820 --> 00:03:20,200 Not tapping the command. 43 00:03:20,560 --> 00:03:22,810 Do show IP OSPF interface. 44 00:03:25,790 --> 00:03:29,450 Allows me to see that OSPF is enabled on the loopback interface. 45 00:03:31,060 --> 00:03:39,130 Going back to privilege mode, I can type the command show ip ospf neighbor to see my neighbors. 46 00:03:39,310 --> 00:03:41,800 And once again, you can see router one and router two. 47 00:03:41,890 --> 00:03:48,220 But I could also do this command show IP OSPF neighbor and specify an individual neighbor. 48 00:03:48,700 --> 00:03:52,030 And this allows me to see more detailed information about the neighbor. 49 00:03:52,570 --> 00:03:59,830 You can see that the neighbor with router id quadruple one and interface address ten 151 is connected 50 00:03:59,830 --> 00:04:03,860 by a serial 1/1 and the neighbor relationship is full. 51 00:04:03,880 --> 00:04:07,360 In other words, we are exchanging updates with one another. 52 00:04:08,630 --> 00:04:09,560 Back on rata one. 53 00:04:09,560 --> 00:04:12,200 You can see that the neighbor relationship with Rada three came up. 54 00:04:13,920 --> 00:04:14,940 Break out of that. 55 00:04:15,610 --> 00:04:18,940 And I can talk to him on show IP route. 56 00:04:20,360 --> 00:04:27,890 And I can see that I've learnt about networks quadruple two, network quadruple three as well as network 57 00:04:27,920 --> 00:04:33,110 ten 130 and Network ten 140. 58 00:04:33,830 --> 00:04:39,710 Notice this gap means that we're doing load balancing because the costs are the same. 59 00:04:40,190 --> 00:04:44,960 In other words, from rather ones point of view to get to network ten 130. 60 00:04:44,990 --> 00:04:50,660 We could either use this link, which is 128 kilobits per second, or we could use this link, which 61 00:04:50,660 --> 00:04:52,720 is also 128 kilobits per second. 62 00:04:52,730 --> 00:04:56,420 So there are two possible paths to use to get to this network. 63 00:04:56,960 --> 00:05:04,280 OSPF supports equal cost load balancing tapping the command show IP OSPF database. 64 00:05:05,970 --> 00:05:14,070 Allows me to view the OSPF topology database and as you can see here for OSPF router with ID quadruple 65 00:05:14,070 --> 00:05:17,850 one process ID one area zero. 66 00:05:18,300 --> 00:05:21,990 We have learnt about three routers ourselves. 67 00:05:22,470 --> 00:05:24,630 Router two and router three. 68 00:05:25,260 --> 00:05:29,400 The number of links on router one is set to six. 69 00:05:29,670 --> 00:05:34,410 The reason for that is a serial link as a link count of two. 70 00:05:34,890 --> 00:05:40,710 Router one has two serial links 01/0 and serial 1/1. 71 00:05:41,010 --> 00:05:43,200 In other words, two plus two equals four. 72 00:05:43,740 --> 00:05:50,580 Router one also has a loopback interface, so plus one equals five and it has a fast ethernet zero zero 73 00:05:50,580 --> 00:05:53,520 interface, so plus one equals six. 74 00:05:54,120 --> 00:06:00,570 I can see that in more detail by typing the command show IP OSPF database and notice this option rather 75 00:06:00,960 --> 00:06:04,860 and then specifying the router ID in this case ourselves. 76 00:06:05,490 --> 00:06:08,070 And you can see once again that an area is zero. 77 00:06:08,820 --> 00:06:16,800 Rada with Rada ID quadruple one has a stub network, which is a loopback interface with an IP address 78 00:06:16,800 --> 00:06:21,930 of quadruple one and mask of slash 32 as well as a point to point link. 79 00:06:22,970 --> 00:06:28,930 Connected to neighboring router quadruple three with local IP address ten 151. 80 00:06:28,940 --> 00:06:32,180 In other words, this serial point to point link. 81 00:06:35,540 --> 00:06:38,660 As well as Stub Network ten 150. 82 00:06:39,770 --> 00:06:40,860 Slash 24. 83 00:06:40,880 --> 00:06:44,930 In other words, the network on the serial link. 84 00:06:46,230 --> 00:06:50,760 It's also connected to a quadruple T with local IP address. 85 00:06:50,760 --> 00:06:52,230 Ten one, two, one. 86 00:06:52,500 --> 00:06:59,100 In other words, this interface and on that interface we have network ten 120. 87 00:07:00,000 --> 00:07:04,080 We are also connected to Network ten 110. 88 00:07:06,090 --> 00:07:07,380 The two count those networks. 89 00:07:08,730 --> 00:07:12,330 We have one, two, three, four. 90 00:07:14,530 --> 00:07:20,350 Five six networks connected to router one notice. 91 00:07:20,350 --> 00:07:23,080 On serial links, there are two entries. 92 00:07:23,440 --> 00:07:30,220 The entry connected to the neighboring router on the point to point link as well as the actual subnet 93 00:07:30,220 --> 00:07:31,720 on that point to point link. 94 00:07:32,740 --> 00:07:41,410 So once again, show IP OSPF database shows me that for our local router we have six as the link count 95 00:07:41,590 --> 00:07:44,710 because there are two entries for the serial links. 96 00:07:45,340 --> 00:07:49,360 This is the topological database which is shared by all routers. 97 00:07:50,050 --> 00:07:55,060 So on router to show ip ospf database. 98 00:07:56,040 --> 00:08:00,870 Well, allow me to see that that router has the same information as Rada one. 99 00:08:01,290 --> 00:08:02,910 It's the same database. 100 00:08:03,750 --> 00:08:12,990 On Router three show IP OSPF database will allow me to see the exact same database link state routing 101 00:08:12,990 --> 00:08:17,490 protocols shared the same database within the network or area. 102 00:08:17,640 --> 00:08:20,340 These three routers on the same area. 103 00:08:20,340 --> 00:08:23,880 So all three of them share the exact same database. 104 00:08:24,510 --> 00:08:28,380 Back on router one, I could type the command debug. 105 00:08:30,190 --> 00:08:32,049 IPOs, OSPF events. 106 00:08:33,700 --> 00:08:37,000 To see event information on router one.