1 00:00:00,450 --> 00:00:06,210 At the moment this network is working correctly as an example out of Falcon ping the loopback of router 2 00:00:06,210 --> 00:00:16,560 one and it can ping gigabit zero zero on router one router one can ping the loopback of router four 3 00:00:16,980 --> 00:00:18,480 and can ping. 4 00:00:20,870 --> 00:00:23,750 The Gigabit zero zero interface on router four. 5 00:00:24,020 --> 00:00:31,040 But in the same way as you have with OSPF version two, you can enable. 6 00:00:32,430 --> 00:00:33,810 Passive interfaces. 7 00:00:33,990 --> 00:00:36,810 So if we use the command passive interface. 8 00:00:37,520 --> 00:00:38,480 Default. 9 00:00:39,380 --> 00:00:41,600 That'll make all interfaces passive. 10 00:00:41,750 --> 00:00:44,570 In other words, the Rada Rada three. 11 00:00:45,280 --> 00:00:51,160 Will not form neighbor relationships on these interfaces or send updates out of those interfaces. 12 00:00:51,520 --> 00:00:54,370 So you can see both neighbor relationships have come down. 13 00:00:55,280 --> 00:00:56,210 Show. 14 00:00:58,840 --> 00:01:01,270 IPV six OSPF neighbor. 15 00:01:01,300 --> 00:01:03,040 They are no neighbor relationships. 16 00:01:03,750 --> 00:01:08,130 Rather one is no longer able to ping rather for. 17 00:01:11,060 --> 00:01:14,090 And rather too we can see that the neighbor relationship has gone down. 18 00:01:14,510 --> 00:01:17,900 Show IPV six OSPF neighbor. 19 00:01:17,930 --> 00:01:21,560 We only have one neighbor relationship. 20 00:01:21,860 --> 00:01:28,370 So from a troubleshooting point of view, if you can't ping through an OSPF network, check that the 21 00:01:28,370 --> 00:01:30,200 neighbor relationships are established. 22 00:01:30,230 --> 00:01:37,700 If the neighbor relationships aren't established, check that OSPF is enabled on all the relevant interfaces 23 00:01:37,700 --> 00:01:39,750 in the right areas. 24 00:01:39,770 --> 00:01:45,170 So make sure that your areas are configured correctly on the relevant interfaces. 25 00:01:46,550 --> 00:01:48,800 So rather three doesn't have a neighbor relationship. 26 00:01:48,830 --> 00:01:53,990 Make sure that OSPF is enabled on the relevant interfaces. 27 00:01:54,170 --> 00:02:02,030 If it is enabled on the interfaces, check your configuration and make sure that you haven't got passive 28 00:02:02,030 --> 00:02:02,930 interfaces. 29 00:02:04,800 --> 00:02:08,430 So as an example here we can see that all interfaces have gone passive. 30 00:02:09,030 --> 00:02:13,110 Or we could use the command show IPV six OSPF interface. 31 00:02:15,860 --> 00:02:17,600 I notice we have this output. 32 00:02:17,630 --> 00:02:20,300 No hellos, passive interface. 33 00:02:21,130 --> 00:02:23,830 And we can see that on gigabit is zero one. 34 00:02:25,510 --> 00:02:28,540 And we can see that on gigabit zero zero. 35 00:02:28,720 --> 00:02:33,460 So check that passive hasn't been configured on the router. 36 00:02:33,700 --> 00:02:40,990 So in this example, what I'll do is disable the passive interface on gigabit zero zero. 37 00:02:43,920 --> 00:02:46,980 So no passive interface interface. 38 00:02:48,760 --> 00:02:50,830 Gigabit zero zero. 39 00:02:51,160 --> 00:02:54,340 And what we should see is that a neighbor relationship is formed and there you go. 40 00:02:54,340 --> 00:02:57,220 So do show IPV six OSPF neighbor. 41 00:02:57,520 --> 00:03:03,790 We can see a neighbor relationship has been established on gigabit zero zero and we could do something 42 00:03:03,790 --> 00:03:06,190 similar on gigabit zero one. 43 00:03:07,000 --> 00:03:09,380 And notice the neighbor relationship has come up. 44 00:03:09,400 --> 00:03:11,770 So be careful with passive interface. 45 00:03:12,070 --> 00:03:20,770 You can set up a one passive interface like gigabit zero one, or you can enable passive interfaces 46 00:03:20,860 --> 00:03:23,500 globally and then disable them. 47 00:03:24,290 --> 00:03:25,250 To do. 48 00:03:26,810 --> 00:03:30,410 So run pipe begin OSPF. 49 00:03:33,170 --> 00:03:40,370 Notice this configuration, we've enabled default passive interfaces, so all interfaces will be passive, 50 00:03:40,520 --> 00:03:44,810 but then we've overridden the passive option on this interface. 51 00:03:44,810 --> 00:03:46,430 And this interface. 52 00:03:46,490 --> 00:03:55,820 Typically you only enable passive interfaces on links to external networks or to user facing VLANs as 53 00:03:55,820 --> 00:04:00,290 an example where you don't want your users to learn OSPF routes. 54 00:04:01,140 --> 00:04:05,880 Another issue may be that OSPF wasn't enabled on an interface. 55 00:04:05,880 --> 00:04:08,850 So do show run interface gigabit. 56 00:04:10,200 --> 00:04:11,250 Zero one. 57 00:04:11,610 --> 00:04:20,740 If this command wasn't configured, the relationship would not form on that interface. 58 00:04:20,760 --> 00:04:25,290 So do show IPV six OSPF neighbor. 59 00:04:26,120 --> 00:04:33,010 Shows us that no neighbor relationship exists on gigabit zero one and that's where this come on do show 60 00:04:33,020 --> 00:04:36,470 IPV six OSPF interface brief is very useful. 61 00:04:36,590 --> 00:04:42,770 We can see very quickly that OSPF was not enabled on this interface. 62 00:04:46,820 --> 00:04:47,090 Now. 63 00:04:47,090 --> 00:04:49,310 What happens if the wrong area was used? 64 00:04:50,000 --> 00:04:53,240 Do show IPV six ospf. 65 00:04:54,930 --> 00:04:55,650 Neighbor. 66 00:04:56,790 --> 00:04:58,980 No neighbor relationship is established. 67 00:04:58,980 --> 00:05:04,860 But note we are getting a warning message about an area mismatch. 68 00:05:05,070 --> 00:05:09,600 We received an update with the incorrect area. 69 00:05:10,050 --> 00:05:15,570 So our local area is three, but the remote area is two. 70 00:05:16,050 --> 00:05:19,590 So we are warned by the rudder about that problem. 71 00:05:19,890 --> 00:05:26,370 So we need to configure the right area and as soon as we do that our neighbour relationship is established. 72 00:05:26,520 --> 00:05:34,050 So be aware that the same troubleshooting options exist in OSPF version three as you have an OSPF version 73 00:05:34,050 --> 00:05:35,430 to the show. 74 00:05:35,430 --> 00:05:40,650 Commands are very similar, output is very similar, the logic is very similar. 75 00:05:40,650 --> 00:05:46,230 But you're using IP version six addresses and protocols rather than IP version for.