1 00:00:01,010 --> 00:00:02,490 Let's do some testing. 2 00:00:04,920 --> 00:00:12,210 One writer one interface cereal 0 1 0 encapsulation. 3 00:00:12,550 --> 00:00:16,270 I've said this to me before I do that. 4 00:00:16,270 --> 00:00:20,000 Notice there are various options and I'll say this too. 5 00:00:20,590 --> 00:00:28,390 And what we should see is that the interface goes down and there you go line protocol these don't show 6 00:00:28,540 --> 00:00:35,140 interface serial 0 1 0 0. 7 00:00:35,270 --> 00:00:39,540 What you'll notice is the physical interfaces up but the line protocol is down. 8 00:00:39,770 --> 00:00:49,600 So there's a problem at the layer to this interface is using PDP where as router to show interface serials 9 00:00:49,600 --> 00:00:53,390 0 1 0. 10 00:00:53,410 --> 00:01:00,910 So what is routed to using as we can see here ratus using HDL see the physical interface is still up 11 00:01:01,280 --> 00:01:06,300 to the line protocol is down because different solutions are being used. 12 00:01:06,310 --> 00:01:16,430 The one side is using the other side is using HTL see physical clock rate is there but the line protocols 13 00:01:16,430 --> 00:01:17,060 are down. 14 00:01:17,310 --> 00:01:21,280 So on the site I'll change the encapsulation 15 00:01:24,180 --> 00:01:32,820 to BP and hopefully we should see the interfaces come up and they you go into faces come up and on the 16 00:01:32,820 --> 00:01:34,510 side interfaces come up. 17 00:01:34,590 --> 00:01:42,960 What I'd like you to see is that different encapsulations can be used on interfaces on a router but 18 00:01:42,990 --> 00:01:44,870 across a point to point link. 19 00:01:44,880 --> 00:01:48,080 Both sides have to agree on encapsulation. 20 00:01:48,300 --> 00:02:05,860 So as an example on this 1841 router Sariel 0 1 0 is using PDP but on this interface serial 0 0 0 encapsulation 21 00:02:05,860 --> 00:02:07,170 is HDL C.. 22 00:02:07,360 --> 00:02:15,730 That means that this cable is using HDL C and this cable is using GPP the 1841 rodded to device needs 23 00:02:15,730 --> 00:02:20,930 to be using PDP and the 17:21 needs to be using HDL. 24 00:02:21,160 --> 00:02:26,270 So the same encapsulation has to be used on both ends. 25 00:02:26,300 --> 00:02:31,760 If I shut down an interface I'm going to shut down. 26 00:02:31,780 --> 00:02:34,370 Serial is 0 1 0. 27 00:02:35,830 --> 00:02:43,370 Notice on this side we see that the interface went down and the line protocol went down. 28 00:02:44,470 --> 00:02:48,590 Show interface serial is 0 1 0. 29 00:02:51,370 --> 00:02:55,920 Here the physical interface has gone down as well as the line protocol. 30 00:02:56,050 --> 00:03:02,640 If there's a problem between the DTV and the DC we are going to see the physical interface go down shut 31 00:03:02,700 --> 00:03:04,830 it on the side. 32 00:03:05,560 --> 00:03:11,760 You should see the interface come up in the same way if I shut it down on this side 33 00:03:16,300 --> 00:03:23,050 we'll see the interface go down on Rotto one and there you go into face went down the line protocol 34 00:03:23,050 --> 00:03:29,200 and don't shut it. 35 00:03:29,300 --> 00:03:31,850 It may take a few seconds and that's because 36 00:03:34,560 --> 00:03:38,030 the keep alive the same every ten seconds on a link. 37 00:03:38,250 --> 00:03:40,640 So it may not be instant. 38 00:03:40,660 --> 00:03:44,130 Here it is because this cable is connected back to back. 39 00:03:44,230 --> 00:03:50,240 But in the real world that may not be true may take a while for the interface to go down to come up. 40 00:03:51,960 --> 00:03:54,390 So what do you need to remember. 41 00:03:54,480 --> 00:04:01,560 It's fairly easy to configure serial interfaces on the one interface. 42 00:04:01,560 --> 00:04:06,730 We changed the encapsulation but on the other we didn't. 43 00:04:06,960 --> 00:04:14,360 So all we need to do is no shut the interface and put an IP address on and configure the relevant bandwidth. 44 00:04:14,730 --> 00:04:21,620 If it is a DC interface like in this example we need to put the clock rate on. 45 00:04:21,840 --> 00:04:31,250 So on DC interfaces you put the clock rate but not on DTV interfaces on a DTV you put the bandwidth 46 00:04:31,560 --> 00:04:35,850 and the relevant encapsulation HPLC once again is the default.