1 00:00:00,600 --> 00:00:02,440 So he our sample network. 2 00:00:02,460 --> 00:00:12,000 We have router one with IP address ten 111 on Fost Ethernet zero zero ten 1211010 which is connected 3 00:00:12,000 --> 00:00:19,650 to our two or two is configured with ten 122 on 010 and ten 131 on serial one. 4 00:00:19,920 --> 00:00:32,009 One or three is configured with ten 1321010 and ten 141 on FOSS Ethernet zero zero or one and all three 5 00:00:32,009 --> 00:00:39,540 are connected via another serial link and are configured with addresses ten 151, one or one and ten 6 00:00:39,540 --> 00:00:41,610 152 on are three. 7 00:00:42,090 --> 00:00:47,730 Please note that the link speed of the serial links have been set to 128 kilobits per second. 8 00:00:48,920 --> 00:00:50,030 Songwriter one. 9 00:00:50,880 --> 00:00:59,280 So run interface serial 1/0 will allow us to see the configuration and see it's got an IP address and 10 00:00:59,280 --> 00:01:02,640 the bandwidth has been configured to 128 kilobits per second. 11 00:01:05,840 --> 00:01:11,330 The same information can be viewed on serial one one IP address with bandwidth. 12 00:01:12,120 --> 00:01:18,240 Show IP protocols will allow me to see that no writing protocols have been enabled on this writer. 13 00:01:20,400 --> 00:01:28,950 So going to global configuration mode, I can now enable OSPF by tapping the command router OSPF and 14 00:01:28,950 --> 00:01:35,790 specifying a process id once again, this process ID is local to the router and does not have to be 15 00:01:35,790 --> 00:01:37,890 the same on all of the routers. 16 00:01:37,890 --> 00:01:40,320 So on router one, I'm going to specify one. 17 00:01:41,320 --> 00:01:47,560 Popping the command do show IP protocols will allow me to see which routing protocols are enabled. 18 00:01:47,650 --> 00:01:56,920 And as you can see here, OSPF is enabled with process ID one and the router ID is set to ten 151. 19 00:01:57,220 --> 00:01:58,180 However. 20 00:01:58,960 --> 00:02:07,420 Topping the commands do show IP OSPF interfaces will allow me to see that OSPF is not enabled on any 21 00:02:07,420 --> 00:02:08,979 interfaces on this router. 22 00:02:09,400 --> 00:02:13,360 OSPF will not form neighbor relationships and will not exchange routes. 23 00:02:14,170 --> 00:02:19,780 For neighbor relationships to be established and for routes to be advertised, you need to top the command 24 00:02:19,780 --> 00:02:20,620 network. 25 00:02:21,540 --> 00:02:30,240 And then specify a network so I could specify ten .1.1.1 the IP address of the Fost Ethernet zero zero 26 00:02:30,240 --> 00:02:31,140 interface. 27 00:02:31,820 --> 00:02:34,820 And then I can specify a wildcard mosque. 28 00:02:35,060 --> 00:02:41,900 This is an inverse mosque similar to an access list with zero in binary means match and one in binary 29 00:02:41,900 --> 00:02:42,860 means ignore. 30 00:02:42,890 --> 00:02:46,310 So this is an exact match on that IP address. 31 00:02:46,460 --> 00:02:50,930 OSPF will only be enabled on fast ethernet zero zero. 32 00:02:51,560 --> 00:02:53,780 You then need to specify an area. 33 00:02:54,730 --> 00:02:57,580 And in this case, I'm going to specify area zero. 34 00:02:57,730 --> 00:03:07,900 The area can be specified as a decimal value in this range or in dotted decimal IP address format. 35 00:03:08,230 --> 00:03:11,590 We're just going to specify the area as area zero. 36 00:03:12,160 --> 00:03:21,400 Now typing the come on do show IP OSPF interface allows me to see that OSPF is enabled on fast Ethernet 37 00:03:21,400 --> 00:03:22,540 zero zero. 38 00:03:22,960 --> 00:03:27,610 The IP address on that interface is ten 111 slash 24. 39 00:03:27,760 --> 00:03:32,110 And the area that that interface is being put into is area zero. 40 00:03:32,590 --> 00:03:40,150 You can see once again that the process ID is one, the router ID is ten 151 and the network type is 41 00:03:40,150 --> 00:03:41,140 broadcast. 42 00:03:41,900 --> 00:03:45,350 Because fast ethernet zero zero is Ethernet. 43 00:03:45,740 --> 00:03:48,590 OSPF will see this as a broadcast media. 44 00:03:49,040 --> 00:03:50,570 The cost is one. 45 00:03:50,840 --> 00:03:56,750 Once again, referring back to the OSPF formula, a 100 meg link will have a cost of one. 46 00:03:57,080 --> 00:04:00,440 Notice the priority is set to one, which is the default. 47 00:04:00,650 --> 00:04:03,410 There is no designated route on this network. 48 00:04:03,890 --> 00:04:05,870 The hello interval is 10 seconds. 49 00:04:06,050 --> 00:04:12,260 The date interval is 40 seconds, so a lot of information can be gathered just through the single command. 50 00:04:12,590 --> 00:04:14,150 Tapping the command again. 51 00:04:15,700 --> 00:04:19,089 Notice we have become the designated Rada. 52 00:04:19,910 --> 00:04:26,070 Al Rata ID is ten 151 and the designated writer ID is ten 151. 53 00:04:26,090 --> 00:04:27,770 In other words, it's us. 54 00:04:28,010 --> 00:04:34,490 Notice the interface IP address is ten 111, which is the IP address and the Fost Ethernet interface. 55 00:04:34,940 --> 00:04:35,720 On Ethernet. 56 00:04:35,720 --> 00:04:41,540 As explained, routers will go through an election to determine the designated router and backup designated 57 00:04:41,540 --> 00:04:48,290 router, and that election has now taken place with our local router becoming the designated router 58 00:04:48,290 --> 00:04:51,470 because there is no other router on this segment. 59 00:04:51,860 --> 00:04:54,440 So we are the de facto designated router. 60 00:04:54,890 --> 00:05:01,850 OSPF, however, has not been enabled on the serial 1/0 interface and serial 1/1 interface. 61 00:05:01,850 --> 00:05:02,870 So let's do that. 62 00:05:02,870 --> 00:05:09,740 Now I can type the command network ten .1. 2 to 1, the IP address of serial 1/0. 63 00:05:10,340 --> 00:05:14,570 Once again put in my wildcard mask once again put in my area. 64 00:05:15,080 --> 00:05:24,620 Now topping the command show IP OSPF interface allows me to see that OSPF is enabled on serial 1/0 as 65 00:05:24,620 --> 00:05:29,210 well as fast Ethernet 0/0 hitting spacebar. 66 00:05:29,240 --> 00:05:33,230 Shows me that OSPF is not enabled on any other interfaces. 67 00:05:33,230 --> 00:05:35,060 So once again, network. 68 00:05:36,500 --> 00:05:39,020 Ten .1.5.1. 69 00:05:39,990 --> 00:05:46,710 Wild Card mosque and our area will enable OSPF on the serial one one interface. 70 00:05:47,800 --> 00:05:59,830 Show IP OSPF interface shows me that OSPF is now enabled on 011010 as well as Fast Ethernet zero zero. 71 00:06:00,900 --> 00:06:01,230 Doing that. 72 00:06:01,230 --> 00:06:02,280 Come on again. 73 00:06:03,640 --> 00:06:07,460 It allows me to see information relating to the serial interfaces. 74 00:06:07,790 --> 00:06:11,870 Notice that on both serial interfaces the process ID is one. 75 00:06:12,110 --> 00:06:16,500 As you would expect, the router ID is ten 151. 76 00:06:16,520 --> 00:06:17,720 As you would expect. 77 00:06:18,460 --> 00:06:21,490 The network type, however, is point to point. 78 00:06:21,880 --> 00:06:28,540 OSPF is intelligent enough to realize that this is a point to point link and thus the OSPF type is set 79 00:06:28,540 --> 00:06:29,590 to zero point to point. 80 00:06:30,070 --> 00:06:35,980 Notice the cost is 781, which is the cost of 128 kilobits per second link. 81 00:06:36,310 --> 00:06:41,350 Once again, the hollow interval is 10 seconds, the date interval is 40 seconds. 82 00:06:41,590 --> 00:06:47,200 But what you won't see here is designated router and backup designated router. 83 00:06:47,590 --> 00:06:53,440 There is no need for an election on a point to point link because there are only two routers communicating 84 00:06:53,440 --> 00:06:54,280 with each other. 85 00:06:54,670 --> 00:06:56,590 So no election has taken place. 86 00:06:56,920 --> 00:07:02,770 So just to give you the full syntax of commands control z, show ip ospf. 87 00:07:03,560 --> 00:07:04,550 Interface. 88 00:07:05,400 --> 00:07:08,370 Shows me the interfaces that OSPF is enabled on. 89 00:07:09,030 --> 00:07:14,610 Show IP protocols will allow me to see the routing protocols enabled on this router. 90 00:07:15,000 --> 00:07:18,900 And as you can see here, OSPF one has been enabled. 91 00:07:18,900 --> 00:07:22,260 The router ID for the local route is ten 151. 92 00:07:22,800 --> 00:07:30,330 The number of areas configured on this router is one with one normal area, no stub areas and no not 93 00:07:30,330 --> 00:07:31,710 so stubby areas. 94 00:07:32,400 --> 00:07:38,430 Stubborn, not so stubby areas are special types of OSPF areas used to reduce the number of routes in 95 00:07:38,430 --> 00:07:39,480 the routing table. 96 00:07:39,840 --> 00:07:44,970 The maximum number of paths that we will load balance across by default is four, but that could be 97 00:07:44,970 --> 00:07:46,320 changed to 16. 98 00:07:46,680 --> 00:07:56,400 We are routing for the following networks ten 111 ten 121 ten 151 Notice the masks we have specified 99 00:07:56,400 --> 00:08:01,470 the individual IP addresses when we entered the network command. 100 00:08:01,890 --> 00:08:06,900 The reference bandwidth is 100 megabits per second, which is the default. 101 00:08:07,200 --> 00:08:12,930 The administrative distance of OSPF is 110 tapping the command show IP route. 102 00:08:15,030 --> 00:08:18,990 Shows me that I only have directly connected routes in my routing table. 103 00:08:19,080 --> 00:08:25,440 The reason why is we have not enabled OSPF on router two and router three, so we are not receiving 104 00:08:25,440 --> 00:08:28,170 routes from either of those routers. 105 00:08:29,090 --> 00:08:31,640 I can talk to command show IP OSPF. 106 00:08:32,750 --> 00:08:38,179 Which gives me a lot of information relating to the OSPF process running on this router. 107 00:08:38,780 --> 00:08:40,909 Once again, process one is being enabled. 108 00:08:41,299 --> 00:08:43,700 The router ID is ten 151. 109 00:08:43,880 --> 00:08:46,640 We can see timers and statistics like this. 110 00:08:46,640 --> 00:08:52,100 For instance, initial SBF scheduled delay 5000 milliseconds. 111 00:08:52,520 --> 00:09:00,650 The router will wait 5 seconds before running the SPFL algorithm when notified of a network going down 112 00:09:00,650 --> 00:09:03,860 or a new network that's been added to the topology. 113 00:09:04,430 --> 00:09:10,280 The idea of this is to allow the network to stabilize before running the OSPF algorithm. 114 00:09:10,760 --> 00:09:17,420 Notice the minimum hold time between two consecutive SPF algorithm calculations is 10 seconds. 115 00:09:17,810 --> 00:09:23,000 So in other words, we will not run the SPF algorithm continuously. 116 00:09:23,330 --> 00:09:27,440 There is a gap of 10 seconds between calculations. 117 00:09:29,210 --> 00:09:35,750 We can see that the backbone Area Zero has been enabled in Misrata and three interfaces have been put 118 00:09:35,750 --> 00:09:36,920 into this area. 119 00:09:37,340 --> 00:09:45,560 No authentication has been enabled on this area and we lost executed the algorithm about 5 minutes ago 120 00:09:45,950 --> 00:09:47,960 and it executed three times. 121 00:09:49,130 --> 00:09:53,480 So let's enable OSPF on router two and see how the output changes. 122 00:09:54,850 --> 00:10:01,930 So in rather to show IP interface brief will allow me to see the interfaces configured on this router.