1 00:00:00,960 --> 00:00:07,350 Now, something that may be a stumbling block for you and often trips up engineers when they first start 2 00:00:07,350 --> 00:00:11,220 out, is logging when they telnet to a router. 3 00:00:12,210 --> 00:00:15,690 So in this example, I'm going to connect to the router 4 00:00:19,260 --> 00:00:22,140 from my local Windows PC. 5 00:00:23,450 --> 00:00:25,310 So I'm going to connect the router 6 00:00:27,560 --> 00:00:29,360 to the outside world 7 00:00:30,340 --> 00:00:32,110 and I'm just going to use my 8 00:00:33,610 --> 00:00:40,510 local area connection card to connect GNS3 to the outside world 9 00:00:42,750 --> 00:00:46,830 and then what I'll do is I'll connect the router to the cloud. 10 00:00:49,920 --> 00:00:58,110 So on router 1 interface f0/1 this is the interface connected to the outside 11 00:00:58,110 --> 00:01:07,830 world, I'm going to know shut the interface and type IP address DHCP so that the router gets an IP address 12 00:01:07,850 --> 00:01:09,120 via DHCP. 13 00:01:10,260 --> 00:01:16,050 So hopefully I should see a message stating that an address has been allocated. 14 00:01:16,770 --> 00:01:17,450 In this case 15 00:01:17,460 --> 00:01:25,320 you can see that an address level 6 in Syslog which is an informational message 16 00:01:26,590 --> 00:01:32,440 shows me that an address has been assigned to the routers interface with this IP address. 17 00:01:34,490 --> 00:01:35,720 So in windows 18 00:01:38,210 --> 00:01:39,950 I'll telnet to the router, 19 00:01:42,020 --> 00:01:44,060 I'm told that I need a password, so 20 00:01:45,300 --> 00:01:57,840 Line VTY 084 login password Cisco, enable password Cisco, obviously in the real world you'll use a 21 00:01:57,840 --> 00:01:58,980 better password than that 22 00:02:01,100 --> 00:02:06,290 but that's fine for our demonstration, so show logging. 23 00:02:07,410 --> 00:02:14,850 Now, according to this, I have debugging a level of monitoring on a monitor. 24 00:02:16,950 --> 00:02:22,800 So let's check the debugging show debug, this is on the console. 25 00:02:24,130 --> 00:02:27,910 You can see OSPF adjacency events, debugging is enabled. 26 00:02:29,040 --> 00:02:34,320 So let's see if we get any output on our telnet session. 27 00:02:36,000 --> 00:02:40,770 I'll shut down the interface on router 2 and then enable it. 28 00:02:42,500 --> 00:02:50,930 So notice I'm getting debugged on the console but nothing is displayed on the telnet session, lots 29 00:02:50,930 --> 00:02:57,320 of debugging on the console, nothing on the telnet session, and that's because you have to type 30 00:02:58,730 --> 00:03:01,280 Terminal monitor or Termmon. 31 00:03:02,530 --> 00:03:11,000 So term monitor or terminal monitor or termmon for short, any one of those options will do. 32 00:03:11,530 --> 00:03:14,800 So let's try now shut the interface on router 2, 33 00:03:17,250 --> 00:03:28,530 no shut it and notice, suddenly I'm seeing debugging messages on both the console as well as the 34 00:03:28,800 --> 00:03:34,240 telnet session, so don't forget that you can set logging and 35 00:03:34,260 --> 00:03:36,680 I'll do that through the console. 36 00:03:37,440 --> 00:03:46,800 You can set the logging for a monitor line, but by default, the output is not displayed on your telnet 37 00:03:46,800 --> 00:03:47,340 session. 38 00:03:47,550 --> 00:03:49,600 You must type terminal monitor. 39 00:03:50,250 --> 00:03:57,900 You don't have to do that on a console. So in router 2 if I type terminal monitor 40 00:03:59,130 --> 00:04:05,940 notice, I'm told that the console already monitors you don't have to enable terminal monitor on the 41 00:04:05,940 --> 00:04:13,440 console by default debugging and Syslog messages will be displayed on the console, but that won't be 42 00:04:13,440 --> 00:04:16,440 displayed on a telnet line. 43 00:04:17,019 --> 00:04:25,140 So as an example, if I press control zed or control Z on the terminal, so the VTY line, I see output 44 00:04:25,890 --> 00:04:27,870 but if I type term no monitor 45 00:04:29,150 --> 00:04:31,800 and do that again, control zed or control z 46 00:04:32,750 --> 00:04:35,600 I don't see anything on the terminal line. 47 00:04:36,920 --> 00:04:44,720 So Termmon, very important to remember that allows you to see debugging messages and console messages, 48 00:04:44,720 --> 00:04:50,120 so Syslog messages on the VTY line, it's not there by default.