1 00:00:00,860 --> 00:00:06,800 The third category of writing protocols is advanced distance vector. 2 00:00:06,870 --> 00:00:15,890 In theory you GOP or enhanced interior gateway writing protocol takes the best of both distance vector 3 00:00:16,460 --> 00:00:22,310 and link states writing protocols and combines that into a single writing protocol. 4 00:00:22,640 --> 00:00:30,310 You may see that the GOP is described as a hybrid writing protocol where it combines elements of both 5 00:00:30,320 --> 00:00:36,440 distance vector and link state into a single writing protocol that isn't entirely true. 6 00:00:36,500 --> 00:00:41,710 And in the GOP videos we'll discuss that in a lot more detail. 7 00:00:41,750 --> 00:00:48,370 In theory the GOP takes the best of distance vector in that it's very easy to configure. 8 00:00:48,380 --> 00:00:55,370 You could configure the GOP on a router as an example by using just two commands and thus it's very 9 00:00:55,370 --> 00:01:01,340 easy to configure in the same way that REPP in the past was easier to configure. 10 00:01:01,490 --> 00:01:08,540 GOP however forms a neighbor relationships in a similar way to link state routing protocols such as 11 00:01:08,540 --> 00:01:09,670 OSPF. 12 00:01:09,740 --> 00:01:18,170 So unlike distance vector writing protocols like REPP that do not form neighbor relationships GOP does 13 00:01:18,290 --> 00:01:20,440 form neighbor relationships. 14 00:01:20,570 --> 00:01:27,680 So in theory it's taking the best of both distance factor and link state and combining them into a single 15 00:01:27,680 --> 00:01:34,520 routing protocol that gives you the power of a link state routing protocol with the ease of configuration 16 00:01:34,850 --> 00:01:37,520 of a distance vector routing protocol. 17 00:01:37,520 --> 00:01:42,440 The disadvantage of LIGO IP is that it's Cisco proprietary. 18 00:01:42,440 --> 00:01:49,580 So unless you are running a pure Cisco network you may have to choose a different writing protocol such 19 00:01:49,580 --> 00:01:51,040 as OSPF. 20 00:01:51,050 --> 00:01:56,510 If however all your devices are Cisco devices job is a very good choice. 21 00:01:56,780 --> 00:01:59,030 It's very easy to configure. 22 00:01:59,180 --> 00:02:00,920 It's very quiet. 23 00:02:00,920 --> 00:02:08,900 It updates very quickly and is a good choice for most enterprise networks that only have Cisco devices. 24 00:02:10,210 --> 00:02:18,580 Another very important concept to understand is administrative distance which is essentially the believability 25 00:02:18,580 --> 00:02:25,270 factor of a rocket when multiple routing protocols are configured on a router and are trying to put 26 00:02:25,270 --> 00:02:28,870 Roths into what's called the routing information base or rub. 27 00:02:28,990 --> 00:02:34,740 Also called the writing table a router will need to decide who to believe. 28 00:02:34,990 --> 00:02:42,620 If OSPF says go left and Elijah up he says go right to get to a network which writing protocol. 29 00:02:42,670 --> 00:02:44,120 Does the router believe. 30 00:02:44,260 --> 00:02:47,520 And which route does it insert into the writing table. 31 00:02:47,770 --> 00:02:54,880 In other words what is the trustworthiness or believability of the routing information back to the rotis 32 00:02:54,880 --> 00:03:03,740 receiving administered of distance is then used as a tiebreaker to determine which way to go when multiple 33 00:03:03,740 --> 00:03:07,560 writing protocols tell the rodded to go different ways. 34 00:03:07,700 --> 00:03:14,730 As an analogy at minister of distance is used as a tiebreaker to determine which way to forward traffic. 35 00:03:14,990 --> 00:03:21,620 If I was B-F says go left and your job he says go right the use uses a minister of distance to determine 36 00:03:21,620 --> 00:03:29,840 which writing protocol it believes most technically what happens is that the writing protocol with the 37 00:03:29,840 --> 00:03:33,640 lowest administrative distance is more believable. 38 00:03:33,770 --> 00:03:39,830 And it's a routing information is inserted into the rub with writing information base or writing table 39 00:03:40,280 --> 00:03:46,230 in preference of other writing protocols that have a higher administrative distance. 40 00:03:46,370 --> 00:03:55,220 So the GOP has a lower administrative distance than OSPF UI GOP has an administered distance of 90 P.F. 41 00:03:55,250 --> 00:03:57,570 has a minister distance of 110. 42 00:03:57,690 --> 00:04:06,920 So internal E.I. GOP would be preferred over a week if so the lower the administer of distance the more 43 00:04:06,920 --> 00:04:09,820 believable a writing protocol is. 44 00:04:10,040 --> 00:04:12,590 You cannot believe anyone more than yourself. 45 00:04:12,590 --> 00:04:21,260 So a Rodda will believe routes that it originates above rats received from neighboring devices a directly 46 00:04:21,260 --> 00:04:28,700 connected interface has a believability factor would minister of distance of zero a static route configured 47 00:04:28,760 --> 00:04:36,410 to a next hop IP address has a minister of distance of one when a static ragi is configured to directly 48 00:04:36,410 --> 00:04:44,300 connected interface it is deemed to be directly connected and therefore has a believability factor or 49 00:04:44,300 --> 00:04:46,890 admonition of distance of zero. 50 00:04:46,910 --> 00:04:52,640 The reason why static routes have such a low administrative distance is that the router believes that 51 00:04:52,670 --> 00:05:00,620 you know more than other routers do you as the administrator are supposed to know what you are doing 52 00:05:01,040 --> 00:05:07,940 and thus the router believes you more than it believes Roths received via routing protocols such as 53 00:05:07,940 --> 00:05:10,510 always P.F. or GOP. 54 00:05:10,910 --> 00:05:15,670 Yeah GOP has an advantage of distance of 90 for internal rats. 55 00:05:15,800 --> 00:05:24,320 Those are rats that originated in the GOP and were not redistributed or taken from a different routing 56 00:05:24,320 --> 00:05:33,470 protocol and then put into the GOP OSPF has a distance of 110 reape has an immersive distance of 120 57 00:05:33,950 --> 00:05:38,170 and unknown Rantz have an image of distance of 255. 58 00:05:38,450 --> 00:05:46,450 As you can see the GOP has a lower administer of distance than repped does and that's because the GOP 59 00:05:46,460 --> 00:05:50,380 is a better or more powerful routing protocol. 60 00:05:50,580 --> 00:05:58,280 Yeah GOP will take bandwidth and delay into account when determining the best route Ripp only uses hop 61 00:05:58,280 --> 00:05:59,140 count. 62 00:05:59,150 --> 00:06:05,770 So yeah GOP seemed to be better than always P.F. which is better than rap.