1 00:00:02,650 --> 00:00:03,820 The network is down. 2 00:00:05,740 --> 00:00:08,370 It's your job to fix the network. 3 00:00:15,210 --> 00:00:17,400 OK, so we need to fix this network. 4 00:00:18,210 --> 00:00:21,810 We've been told event to simulate the power outage. 5 00:00:22,290 --> 00:00:26,590 We need to click the power cycle devices, button in in packet tracer. 6 00:00:27,210 --> 00:00:28,610 So I'll click that button. 7 00:00:29,400 --> 00:00:34,050 we're told that configurations not in the startup configuration will be lost. 8 00:00:34,770 --> 00:00:36,720 Do we want to reset the network? 9 00:00:37,260 --> 00:00:38,190 I'm going to say yes. 10 00:00:39,650 --> 00:00:45,200 As you can see here, router 2, has booted into ROM Monitor mode. 11 00:00:46,330 --> 00:00:47,830 Router 1 is still booting up. 12 00:00:50,500 --> 00:00:51,660 Router 3 is booting up, 13 00:00:55,860 --> 00:00:59,160 But we told of that test ban is missing. 14 00:01:01,490 --> 00:01:07,040 So the fall is not accessible and a default boot fall is being used. 15 00:01:10,930 --> 00:01:13,960 So we've definitely got problems in the network. 16 00:01:14,980 --> 00:01:21,080 I'm going to start fixing the network by starting with router 2, Now in ROM monitor mode, I can see 17 00:01:21,640 --> 00:01:26,590 I can see available commands by using the question mark and enter command. 18 00:01:27,070 --> 00:01:36,160 So use question mark and enter to view available commands or use help to view the available commands. 19 00:01:36,700 --> 00:01:40,280 Notice how ROM monitor increments in number 20 00:01:40,330 --> 00:01:42,130 every time a command is used. 21 00:01:42,820 --> 00:01:44,710 Now this command conf 22 00:01:44,710 --> 00:01:49,300 reg allows us to set the configuration register utility. 23 00:01:50,020 --> 00:01:53,190 In other words, we set of the configuration register value. 24 00:01:53,840 --> 00:01:55,480 So I'm going to use confreg 25 00:01:55,660 --> 00:02:02,020 0x2102 to set the configuration register two normal boot. 26 00:02:02,950 --> 00:02:07,050 Now if you're not sure what the configuration register values are. 27 00:02:07,630 --> 00:02:14,320 Do a search in Google or your favorite search engine for Cisco configuration register. 28 00:02:16,100 --> 00:02:22,340 My first hit is use of the configuration register on all Cisco routers. 29 00:02:23,030 --> 00:02:27,320 So this document shows us the configuration register values. 30 00:02:28,370 --> 00:02:29,480 I want to scroll down. 31 00:02:30,930 --> 00:02:37,380 In the document, we can see that the show version command shows us the configuration register value 32 00:02:38,070 --> 00:02:42,470 when in normal boot mode, we are not currently there 33 00:02:42,930 --> 00:02:45,150 we are in ROM monitor mode. 34 00:02:47,870 --> 00:02:53,270 Here are a list of configuration register settings and the router behavior. 35 00:02:53,960 --> 00:02:56,240 This is the one that I want to use. 36 00:02:56,870 --> 00:03:06,930 It ignores break, boots into ROM if initial boot fails, and sets the console speed to 9600 bits. 37 00:03:07,640 --> 00:03:12,830 That is essentially a default boot value on Cisco routers. 38 00:03:14,960 --> 00:03:16,850 You can set other values 39 00:03:18,110 --> 00:03:23,640 such as 0x2142 which ignores the contents of NVRAM 40 00:03:24,200 --> 00:03:30,980 you want to set the configuration register to this value when doing password recovery on a router. 41 00:03:32,070 --> 00:03:39,540 You can configure the configuration register in global configuration mode when a router has booted successfully 42 00:03:39,900 --> 00:03:46,230 by using the config register command, our router in this example has not booted successfully. 43 00:03:46,680 --> 00:03:50,180 We are in ROM monitor mode or ROMON mode. 44 00:03:51,000 --> 00:03:57,570 We can set the configuration register value by using this command once again and then power cycling 45 00:03:57,590 --> 00:03:58,280 the router. 46 00:03:59,380 --> 00:04:01,050 So I've said it to that value. 47 00:04:01,630 --> 00:04:06,990 This command will allow us to perform a system, reset or reboot. 48 00:04:07,680 --> 00:04:10,560 So reset the router is now booting up. 49 00:04:11,400 --> 00:04:16,110 Notice it's now loading the ISR bin file. 50 00:04:16,829 --> 00:04:19,709 In other words, it's loading the operating system. 51 00:04:20,399 --> 00:04:28,020 So that looks a lot better than what we saw previously when the router booted into ROM monitor mode. 52 00:04:28,740 --> 00:04:35,640 Notice in this example, I can press a return to get started and I can see a router prompt type enable 53 00:04:36,330 --> 00:04:39,690 password is Cisco, show IP interface brief. 54 00:04:41,640 --> 00:04:44,940 We can see some configuration on the rauda. 55 00:04:46,110 --> 00:04:55,740 Such as IP addresses, show IP protocols, we can see that the routing protocol enabled is EIGRP in Autonomous 56 00:04:56,130 --> 00:04:57,180 in autonomous system 57 00:04:57,250 --> 00:04:57,850 100, 58 00:04:58,620 --> 00:05:00,180 So that looks a lot better. 59 00:05:00,900 --> 00:05:07,560 So let's confirm what the configuration register is set to show version. 60 00:05:08,040 --> 00:05:13,170 Shows us that the configuration register is set to this. 61 00:05:14,070 --> 00:05:15,890 Now, that's what it should be set to. 62 00:05:16,560 --> 00:05:19,680 We changed that to ROM monitor mode. 63 00:05:20,340 --> 00:05:28,860 However, if I configured it as a 0x2100 that causes the router to boot into ROM 64 00:05:28,860 --> 00:05:29,610 monitor mode. 65 00:05:30,330 --> 00:05:31,230 So show version, 66 00:05:33,790 --> 00:05:37,680 notice, this is the current configuration register value. 67 00:05:38,380 --> 00:05:40,290 The next value will be this 68 00:05:40,780 --> 00:05:45,280 and notice what happens if I reload without saving the configuration, 69 00:05:46,060 --> 00:05:47,920 I end up in ROM monitor mode. 70 00:05:48,270 --> 00:05:54,000 ROM Monitor is set separately to the running configuration of a router. 71 00:05:54,520 --> 00:06:02,680 So even though I didn't save the running configuration after making a change, the router rebooted into 72 00:06:02,680 --> 00:06:03,760 ROM monitor mode. 73 00:06:04,360 --> 00:06:05,360 So again, question mark 74 00:06:05,380 --> 00:06:11,770 enter confreg 0x2102, reset 75 00:06:12,550 --> 00:06:19,530 that will hopefully boot the router back to where it was and restore the startup configuration of the 76 00:06:19,540 --> 00:06:20,050 router. 77 00:06:21,870 --> 00:06:29,640 It's important that, you know, configuration register settings such as 2101, that in the 78 00:06:29,640 --> 00:06:33,690 old days booted a router into bootstrap mode. 79 00:06:34,200 --> 00:06:37,290 That's commonly ignored on modern routers today. 80 00:06:39,220 --> 00:06:42,160 2102 is standard to boot, 81 00:06:42,760 --> 00:06:44,200 2100, 82 00:06:46,090 --> 00:06:49,720 not shown here, boots, the router into ROM monitor mode, 83 00:06:51,110 --> 00:06:52,760 and 2142 84 00:06:54,180 --> 00:07:00,780 allows you to bypass NVRAM. Note, these are hexadecimal values 85 00:07:01,290 --> 00:07:03,500 that's indicated by 0x. 86 00:07:04,050 --> 00:07:05,400 So this is a hex value. 87 00:07:05,670 --> 00:07:07,490 In other words, four binary bits, 88 00:07:07,890 --> 00:07:09,300 In other words, 00 89 00:07:09,300 --> 00:07:10,180 10, 90 00:07:10,200 --> 00:07:10,920 in binary, 91 00:07:11,490 --> 00:07:13,950 this is three zeros and a one in binary. 92 00:07:14,400 --> 00:07:16,920 This is a 0100 in binary 93 00:07:17,430 --> 00:07:20,430 and this is again 0010 94 00:07:20,730 --> 00:07:21,390 in binary. 95 00:07:22,920 --> 00:07:24,510 OK, so the router has booted up. 96 00:07:25,380 --> 00:07:26,670 That looks a lot better. 97 00:07:27,960 --> 00:07:33,210 Show IP interface brief shows us our IP addresses. 98 00:07:33,900 --> 00:07:35,910 We can see that to the loop back is up 99 00:07:36,540 --> 00:07:42,850 but those interfaces down because there's a problem with router 1. 100 00:07:44,220 --> 00:07:50,640 So at the moment, based on this configuration, it looks like this router has been fixed. 101 00:07:51,210 --> 00:07:59,610 Show version again shows us that to the configuration register is set to this, which is the way we 102 00:07:59,610 --> 00:08:00,660 want it set.