1 00:00:00,860 --> 00:00:04,290 So what are some of the benefits or advantages of a link state. 2 00:00:04,310 --> 00:00:05,670 Writing protocols. 3 00:00:05,960 --> 00:00:13,490 Well firstly Foster convergence changes are reported immediately and link state writing protocols tend 4 00:00:13,490 --> 00:00:19,430 to converge a lot quicker than distance vector writing protocols such as Ripp. 5 00:00:19,430 --> 00:00:26,600 Now that said the GOP which is an enhanced distance vector routing protocol does also converge very 6 00:00:26,600 --> 00:00:27,680 quickly. 7 00:00:27,680 --> 00:00:35,870 It has the simplicity of configuration of a distance vector writing protocol but does have many of the 8 00:00:35,870 --> 00:00:42,950 advantages of a link state rodding protocol link state routing protocols are also more robust as the 9 00:00:42,950 --> 00:00:43,660 rod is. 10 00:00:43,740 --> 00:00:52,280 Note the full topology of the network or area they just tend to be less susceptible to writing loops 11 00:00:52,610 --> 00:00:55,310 because of the greater visibility of the network. 12 00:00:56,360 --> 00:01:03,490 Rajahs know the topology and can thus work out the best route to every destination link state packets 13 00:01:03,490 --> 00:01:07,300 are also sequenced and acknowledged within always P.F.. 14 00:01:07,370 --> 00:01:15,140 So if an update is not received by a router it will be retransmitted REPP it doesn't form neighbor relationships 15 00:01:15,170 --> 00:01:18,720 or peer relationships but OSPF does. 16 00:01:19,130 --> 00:01:27,860 So if one Rodda sends an update to a peer and one that doesn't acknowledge receipt of the writing update 17 00:01:28,460 --> 00:01:31,520 the ratable retransmit the update. 18 00:01:31,520 --> 00:01:39,280 The Hauraki old design of OSPF and other links state running protocols optimizes resources. 19 00:01:39,440 --> 00:01:46,170 It allows for smaller writing tables because of address summarization and fewer shortest path. 20 00:01:46,190 --> 00:01:53,660 First of calculations because of address hiding essentially if the network is designed properly some 21 00:01:53,660 --> 00:02:01,950 routers will have very small writing tables compared to others and will do for few calculations. 22 00:02:01,960 --> 00:02:10,940 Rod is an area one for example will not be a way of all the routes in area to area 3 because of the 23 00:02:10,940 --> 00:02:18,830 use of summarization on the area border routers and the configuration of spatial areas such as stub 24 00:02:18,920 --> 00:02:27,140 areas the Rockhill design also allows a link state running protocols to scale and thus work in much 25 00:02:27,230 --> 00:02:33,860 larger environments than distance vector writing protocols could large ISP on the Internet for example 26 00:02:34,310 --> 00:02:43,220 may run OSPF or ISIS internally within their autonomous systems OSPF and ISIS are preferred to writing 27 00:02:43,220 --> 00:02:49,970 protocols such as REPP because there are a lot more scaleable link state writing protocols. 28 00:02:49,970 --> 00:02:53,940 However Orsa have group X or disadvantages. 29 00:02:54,110 --> 00:02:59,690 The first disadvantage is that they have a greater demand for resources. 30 00:02:59,690 --> 00:03:05,100 They end distance vector writing protocols do link state routing protocols require more memory. 31 00:03:05,300 --> 00:03:07,820 The routers have multiple tables. 32 00:03:07,940 --> 00:03:11,240 So for example they'll have appear table or neighbor table. 33 00:03:11,540 --> 00:03:19,220 They'll have a typology table or link state database musical in Ellis D-B database and they have a writing 34 00:03:19,220 --> 00:03:20,550 table. 35 00:03:20,570 --> 00:03:28,250 More memory is required to hold multiple tables than would be necessary with a distance vector writing 36 00:03:28,250 --> 00:03:29,330 protocol. 37 00:03:29,330 --> 00:03:37,610 There's also more demand on the CPQ of the rod or a switch when running OSPF or ISIS the dextrous algorithm 38 00:03:37,790 --> 00:03:43,840 can be very process intensive especially when there are a lot of changes in the topology linked state 39 00:03:43,850 --> 00:03:44,690 writing protocols. 40 00:03:44,690 --> 00:03:49,310 Also require strict design's in OSPF as an example. 41 00:03:49,310 --> 00:03:54,640 Area 0 is always required when you have more than one area. 42 00:03:54,680 --> 00:04:01,430 All other areas have to touch the backbone area for areas zero all traffic from one area to another 43 00:04:01,430 --> 00:04:04,800 area has to traverse the backbone area. 44 00:04:04,970 --> 00:04:11,100 The configuration of OSPF is far more complex then distance vector writing protocols such as rep. 45 00:04:11,100 --> 00:04:17,240 However the advantages of link state routing protocols generally far outweigh the disadvantages. 46 00:04:17,360 --> 00:04:20,810 And this is especially true in large environments. 47 00:04:21,050 --> 00:04:26,300 Thus in large typologies OSPF is seen as a much better choice than Rp.