1 00:00:01,260 --> 00:00:07,830 You can also view the connections to the router or switch by using the show users command, so show user 2 00:00:07,830 --> 00:00:17,250 shows us that we connected via console zero, but we also connected via a telnet session from this IP 3 00:00:17,250 --> 00:00:17,670 address. 4 00:00:18,630 --> 00:00:20,580 So if I exit out of the telnet session, 5 00:00:22,590 --> 00:00:30,540 show users now shows that we only connected via the console, I'll log in via the telnet session again. 6 00:00:31,690 --> 00:00:35,170 Show users shows us that the telnet session is now active. 7 00:00:36,920 --> 00:00:42,080 I'll jump back to router 1 using the keystrokes control shift 6 x 8 00:00:43,200 --> 00:00:53,100 and open up another telnet session, show users now shows us that David is connected to VTY 0 as 9 00:00:53,100 --> 00:00:57,570 well as VTY 1 control shift 6 X. 10 00:00:58,570 --> 00:01:04,690 Open up another session, control shift 6 X do another. 11 00:01:06,990 --> 00:01:13,080 So we now have four VTY sessions open, jump back. 12 00:01:14,970 --> 00:01:16,490 Now, the telnet session. 13 00:01:19,030 --> 00:01:25,120 Show users, we're now connected and what's interesting is notice the username is not case sensitive in this 14 00:01:25,120 --> 00:01:27,550 example, but the password is case sensitive. 15 00:01:28,180 --> 00:01:34,120 So we've got 1,2,3,4,5 VTY sessions, 16 00:01:34,780 --> 00:01:37,060 if I jump back to the router now, router 1 17 00:01:37,950 --> 00:01:49,410 and try and telnet again, notice the session is refused because we only enabled five VTY sessions from 18 00:01:49,410 --> 00:01:50,250 0 to 4. 19 00:01:52,470 --> 00:01:59,800 At the moment, 5 VTY sessions are being used, so it's 6, 1 is refused or rejected. 20 00:02:00,690 --> 00:02:03,990 Now, here we could clear line 98 21 00:02:05,870 --> 00:02:12,860 by using the command clear line and specifying a number so we could say 98, so just to show you that 22 00:02:12,860 --> 00:02:23,270 again, we could clear this line or we could clear the VTY, so clear line 98 confirm show users, 23 00:02:24,400 --> 00:02:33,940 98 has been disconnected and now on router 1, we can telnet back to router 2, so we have 24 00:02:33,940 --> 00:02:36,240 our session on line 98. 25 00:02:37,070 --> 00:02:45,220 Reason why is, when you type show line, you'll see that the console is VTY 0. 26 00:02:45,820 --> 00:02:53,520 The auxiliary port on the router is line 97 and the first VTY is line 98. 27 00:02:54,160 --> 00:03:00,100 That's to do with asynchronous modules that you can insert into router which you use what are called TTY 28 00:03:00,100 --> 00:03:00,550 lines. 29 00:03:01,450 --> 00:03:05,290 In this case, I'll telnet to a physical router that I've got running locally here 30 00:03:07,500 --> 00:03:08,460 and I'll log in. 31 00:03:12,650 --> 00:03:21,890 This is a 3640 router show line, shows me that I have a console as well as a lot of TTY lines, these 32 00:03:21,890 --> 00:03:28,370 allow me to implement reverse telnet sessions and then an auxiliary connection and then my VTY sessions 33 00:03:28,370 --> 00:03:29,640 on this router. 34 00:03:30,620 --> 00:03:35,150 So show line once again, first line is, is the console. 35 00:03:36,820 --> 00:03:43,990 Then we have a range of TTYs, then the auxillary line and then VTY lines, hence the number 36 00:03:44,620 --> 00:03:52,810 of these VTY lines is not 1 or 2 because you can have reverse console connections on a router. 37 00:03:53,170 --> 00:03:56,580 In the old days, this was used for asynchronous modems. 38 00:03:56,920 --> 00:04:02,620 So the really old days on routers, we had asynchronous modems and we would connect via those modems 39 00:04:02,830 --> 00:04:04,840 on various TTY lines. 40 00:04:05,380 --> 00:04:06,430 So just type show line 41 00:04:06,430 --> 00:04:10,510 if you're not sure what the numbers are, that will vary from device to device. 42 00:04:11,350 --> 00:04:22,750 So on this virtual switch show line shows me that the auxilliary port is line 1 and the VTY line is line 43 00:04:22,750 --> 00:04:30,790 2 because it doesn't support TTY asynchronous modems, whereas a router such as a 3725 does. 44 00:04:31,420 --> 00:04:41,530 So I could also type clear line VTY and specify number so 0 and the connection was closed. 45 00:04:42,640 --> 00:04:43,720 So I'll telnet back 46 00:04:46,580 --> 00:04:50,210 my username is David, not Cisco show line 47 00:04:51,420 --> 00:04:59,820 shows me various lines, show user or uses shows me that at the moment, this is the only active 48 00:04:59,820 --> 00:05:00,190 VTY line. 49 00:05:00,210 --> 00:05:03,490 You can also see the star associated with a VTY line. 50 00:05:04,020 --> 00:05:06,290 The other sessions would have timed out because of a timer. 51 00:05:07,290 --> 00:05:13,290 So once again, if I jump back, control shift 6 x another telnet session, 52 00:05:15,750 --> 00:05:25,710 show line, you can see the console is active and so are both these VTY lines, show users shows me that 53 00:05:25,710 --> 00:05:32,280 I have two connections VTY 0 and VTY 1, clear line 99. 54 00:05:33,330 --> 00:05:37,950 Notice the connection was closed, on this router show 55 00:05:37,960 --> 00:05:44,130 sessions shows me my current sessions and then I could do something like Disconnect, which will disconnect 56 00:05:44,130 --> 00:05:45,800 the last active session. 57 00:05:46,380 --> 00:05:51,440 So Show Sessions shows me that 6 was closed. 58 00:05:53,380 --> 00:05:56,080 I could also do it this way, Disconnect 3, 59 00:05:57,720 --> 00:06:05,550 show sessions, 3s not available, if I want to restore session, I could just simply select the 60 00:06:05,550 --> 00:06:07,560 connection number. So 1 61 00:06:08,190 --> 00:06:09,960 but as you can see, that's been closed. 62 00:06:11,900 --> 00:06:20,050 So shows session 2 that was closed by the remote host, 4 that was closed, 5 that was closed. 63 00:06:20,600 --> 00:06:29,890 So I have no active sessions at the moment if I telnet it back to the router and logged in control shift 6 x 64 00:06:30,440 --> 00:06:31,310 to take me back, 65 00:06:33,600 --> 00:06:34,680 show sessions 66 00:06:35,650 --> 00:06:40,620 select session 1, I notice it resumes it and I am now on router 2.