1 00:00:08,860 --> 00:00:12,230 This is one of multiple SPF videos. 2 00:00:12,400 --> 00:00:19,380 I was asked to explain Oh SPF multiple areas and this is one of multiple videos helping explain how 3 00:00:19,450 --> 00:00:23,590 SPF works when you have multiple areas configured. 4 00:00:23,590 --> 00:00:31,840 Here's a question for you in this topology which are SPF Rodda types are you able to identify as an 5 00:00:31,840 --> 00:00:40,390 example which rorters in this topology or area border Rodders or a bypass which Rada or routers or backbone 6 00:00:40,390 --> 00:00:48,490 routers which Rada or Rodders or internal routers which Rado or Rogers or ESB Rs or autonomous system 7 00:00:48,490 --> 00:00:49,330 border Rodders. 8 00:00:49,860 --> 00:00:57,970 So in this topology we have EAI GOP running on the left hand side then we have 0 SPF Area 1 0 SPF area 9 00:00:57,970 --> 00:01:08,800 0 and 0 SPF Area 2 and AVR or area border router is a router that has interfaces in multiple areas so 10 00:01:08,800 --> 00:01:16,930 as an example rather three is an area border Rada because it has an interface in Area One and an interface 11 00:01:16,930 --> 00:01:26,230 an area zero root of 5 is an area of border rather because it has an interface in area 0 and an interface 12 00:01:26,230 --> 00:01:35,310 an area to it to is an autonomous system border Roorda because it has an interface configured in a different 13 00:01:35,400 --> 00:01:36,950 routing protocol. 14 00:01:37,050 --> 00:01:46,280 In this case the GOP and it has an interface configured in 0 SPF so write it to as an ESB are were autonomous 15 00:01:46,290 --> 00:01:54,530 system border Radha wrote a three and wrote a five or area border Rodders or a B RS wrote a four is 16 00:01:54,530 --> 00:02:03,770 a back bone Rada or backbone area Rada it is a Rada with interfaces in the backbone area now is can 17 00:02:03,770 --> 00:02:11,750 take on multiple roles so wrote a three and wrote a five are also backbone routers in that they have 18 00:02:11,750 --> 00:02:18,570 interfaces in the backbone or area zero but if you will off to this question I would answer that draw 19 00:02:18,570 --> 00:02:27,350 to three and write a five hour area Border Roads area border Rogers always touch the backbone area virtual 20 00:02:27,350 --> 00:02:33,260 links or out of the scope of the CCMA but I will discuss how to configure virtual links which allow 21 00:02:33,260 --> 00:02:44,180 you to pull or extend the backbone area across another area so area zero would be extended across another 22 00:02:44,180 --> 00:02:51,770 area such as area one to allow an area border rata to have an interface in the backbone area and meet 23 00:02:51,860 --> 00:03:00,230 the criteria that an area of border road must touch the backbone area road a six is an internal radar 24 00:03:00,800 --> 00:03:04,850 it's a Rada with interfaces only in an internal area. 25 00:03:05,030 --> 00:03:07,520 In other words area two. 26 00:03:07,620 --> 00:03:14,450 So now that we know the road types let's configure these rotors these writers have just booted up and 27 00:03:14,450 --> 00:03:15,980 have no configuration 28 00:03:19,440 --> 00:03:25,690 so I'll bypass the initial configuration of the routers so that we can configure them manually so on 29 00:03:25,700 --> 00:03:33,970 rudder one this is the rudder on the left hand side I'm going to configure interfaces in these subnets 30 00:03:34,000 --> 00:03:45,500 as per the diagram as well as configure a loop back on the routers with a IP address of the right a 31 00:03:45,500 --> 00:03:46,910 name. 32 00:03:47,000 --> 00:03:48,230 So this is rather one. 33 00:03:48,320 --> 00:03:50,700 So we'll configure the loop back as follows. 34 00:03:50,710 --> 00:03:57,680 So do show IP interface brief shows us the IP addresses configured on the router now this product will 35 00:03:57,740 --> 00:04:08,040 only run EAI GOP so we'll configure ya job P on this rather. 36 00:04:08,310 --> 00:04:17,280 In this example in autonomous system 100 and I'm gonna configure ya GOP on all interfaces of the router 37 00:04:19,610 --> 00:04:24,570 I'll also turn off automatic summarization so do show IP. 38 00:04:25,030 --> 00:04:33,080 Ya GOP interface shows us that you and your PS enabled on the gigabit 00 interface and the loop back 39 00:04:33,080 --> 00:04:42,830 interface has brought it to configure a hostname of right to go into the gigabit zero interface. 40 00:04:42,840 --> 00:04:54,690 No shut up and give it an IP address of 10 1 1 2 slash 24 mosque interface gigabit 0 1 IP address 10 41 00:04:54,690 --> 00:05:03,690 1 2 1 slash 24 mosque and I'll create a loop back of quadruple 2. 42 00:05:04,780 --> 00:05:09,530 Now this Rada needs to run to writing protocols. 43 00:05:09,530 --> 00:05:21,690 Firstly needs to run job P and I want to enable ya job P only on gigabit 00 so notice the IGP neighbour 44 00:05:21,690 --> 00:05:32,040 relationship has come up so do show IPR GOP neighbor shows us the neighbor relationship to show IP interface 45 00:05:32,040 --> 00:05:45,300 brief shows us that the IP address configured on gigabit 00 is this 10 1 1 2 and do show run pipe section 46 00:05:45,330 --> 00:05:55,670 II GOP shows us that we've only configured EAI GOP on that interface will enable OS SPF in this example 47 00:05:55,760 --> 00:06:10,410 on 10 1 2 1 This is the gigabit 0 1 interface and I'll configure it in Area 1 so to show IP SPF interface 48 00:06:10,530 --> 00:06:21,360 grief shows us that 0 SPF is enabled on gigabit 0 1 in Area 1 and process I.D. 1 process idea was this 49 00:06:21,360 --> 00:06:29,700 no area no we configured over there after a while we'll see the state go to D.R. if we don't configure 50 00:06:29,950 --> 00:06:33,300 rod a 3 quickly but I'm not going to do that right now. 51 00:06:34,990 --> 00:06:39,100 Rider 2 is an autonomous system border rider. 52 00:06:39,100 --> 00:06:44,220 We need to do what's called redistribution from one riding protocol to another. 53 00:06:44,320 --> 00:06:54,070 So basically we need to translate if you like or import routes from one riding protocol into another. 54 00:06:54,070 --> 00:07:02,040 This is very similar to translating a language like French into English or English into Spanish. 55 00:07:02,080 --> 00:07:09,960 We are going to translate routes from one routing protocol into another often as it is in the real world. 56 00:07:10,060 --> 00:07:14,780 When you translate from one language to another you can lose meaning. 57 00:07:15,010 --> 00:07:22,610 So sometimes words in one language don't quite mean the same thing in another language and that's true. 58 00:07:22,610 --> 00:07:30,420 When you do redistribution Yai GOP supports different metrics or different ways of determining the best 59 00:07:30,420 --> 00:07:33,010 route when compared to always P.F.. 60 00:07:33,030 --> 00:07:41,310 So when we redistribute GOP into a SPF we can change what's called the seed metric or SPF we'll set 61 00:07:41,310 --> 00:07:42,660 it by default. 62 00:07:42,690 --> 00:07:49,470 We can also change the default cost of a rocket that's redistributed. 63 00:07:49,850 --> 00:07:53,530 Yeah GOP uses bandwidth and delay to determine the best route. 64 00:07:53,790 --> 00:08:00,210 Oh SPF doesn't understand that it only understands bandwidth so you typically need to specify a seat 65 00:08:00,240 --> 00:08:03,570 metric when you redistribute right into a writing protocol. 66 00:08:03,900 --> 00:08:12,030 Oh SPF has a default but notice when we redistribute 0 SPF into EAI GOP we gonna want to specify a metric 67 00:08:12,540 --> 00:08:19,210 and you'll often see the metric written something like this. 68 00:08:20,800 --> 00:08:27,010 So we are taking rights from 0 SPF and advertising them into EAI GOP and we are also advertising rots 69 00:08:27,010 --> 00:08:30,820 from the GOP into 0 SPF. 70 00:08:30,820 --> 00:08:35,560 That's what an area border Roddick does at the moment. 71 00:08:35,560 --> 00:08:42,820 I've only enabled a SPF on gigabyte 0 1 and ya GOP on gigabit 00. 72 00:08:42,970 --> 00:08:52,820 What I'll do with the loop back is advertised that into SPF so I'll advertise this network into 0 SPF. 73 00:08:52,930 --> 00:09:01,530 So now when we use the command show IP SPF database you can see different LSA types in the database. 74 00:09:01,630 --> 00:09:06,070 We've got what's called LSA type 1 or router LSA. 75 00:09:06,280 --> 00:09:17,000 At the moment we only have one product in the database we have LSA type 2 or summary LSA is did make 76 00:09:17,000 --> 00:09:17,750 a mistake here. 77 00:09:17,750 --> 00:09:21,200 And notice I put that interface into area 0. 78 00:09:21,230 --> 00:09:33,410 I actually want to put that in to Area One hence us saying area zero and area 1 in the link state database 79 00:09:34,160 --> 00:09:39,990 7 to remove that from area 0 and put that into Area 1. 80 00:09:40,010 --> 00:09:43,430 So show IP who SPF database. 81 00:09:43,550 --> 00:09:53,840 We only see Area 1 in the database for type 1 and Type 2 aliases Type 1 is once again rather aliases 82 00:09:54,320 --> 00:09:59,210 type 2 or summary aliases and we have what are called Type 5 LSD. 83 00:09:59,300 --> 00:10:02,870 These are rats that came from a different routing protocol. 84 00:10:02,870 --> 00:10:10,370 In other words they were redistributed by an ace PR autonomous system border rider into a waste P.F. 85 00:10:10,730 --> 00:10:13,660 and that's what brought it to is doing in the topology. 86 00:10:13,940 --> 00:10:21,140 So at the moment if we type show IP round we will see the loot back of Route 1 in the running table 87 00:10:21,590 --> 00:10:32,780 as a yard GOP rant and on router 1 we see the loop back of it to advertised into EAI GOP as an external 88 00:10:32,780 --> 00:10:41,590 route it was redistributed from 0 SPF into yo GOP and that's also true for this right. 89 00:10:41,630 --> 00:10:43,510 So those are called external rots. 90 00:10:43,520 --> 00:10:46,660 They came from a different writing protocol. 91 00:10:46,670 --> 00:10:51,060 Hope you found this video useful if it's been of benefit to you please like it. 92 00:10:51,060 --> 00:10:53,510 And please subscribe to my YouTube channel. 93 00:10:53,510 --> 00:10:55,180 I wish you all the very best.