1
00:00:00,710 --> 00:00:07,610
On the Cisco ACS server, we need to go to network configuration and add a triple A client.

2
00:00:08,510 --> 00:00:10,880
In other words, we need to add the Cisco router.

3
00:00:12,130 --> 00:00:19,990
We need to specify the hostname of the router, so I'm gonna call this router 1 and then we need to specify

4
00:00:19,990 --> 00:00:21,610
the IP address of the router

5
00:00:23,100 --> 00:00:27,480
10.1.1.201. The key that we used

6
00:00:33,840 --> 00:00:37,070
was Cisco, shown over here.

7
00:00:40,720 --> 00:00:48,070
So we need to specify Siska as the key and we are going to authenticate in this example using Tacacs

8
00:00:48,250 --> 00:00:52,120
Cisco iOS, there are other options such as Radius

9
00:00:52,390 --> 00:00:59,170
but we'll use Tacacs in this example and I'm going to click, submit and apply to apply that configuration.

10
00:01:02,110 --> 00:01:06,520
Once again, under users, we only have a user called Admin.

11
00:01:08,300 --> 00:01:16,400
So now let's test whether we can log back in to Router 1 as David, so well enter David and the password

12
00:01:17,060 --> 00:01:23,000
notice authentication has failed on the Tacacs server going to reports and activity.

13
00:01:23,900 --> 00:01:25,550
We can look at failed attempts

14
00:01:26,500 --> 00:01:33,670
and we can see here that we've got a failed attempt for David, external database user invalid or bad

15
00:01:33,670 --> 00:01:34,480
password.

16
00:01:36,420 --> 00:01:40,530
I'll login as Mary, username Mary, password Cisco.

17
00:01:41,630 --> 00:01:45,620
I'll refresh the logged in failures and notice Mary

18
00:01:46,860 --> 00:01:47,610
has failed.

19
00:01:48,600 --> 00:01:59,040
But if we log in is Admin Cisco, the authentication passes and we are able to access the router show

20
00:01:59,040 --> 00:02:02,070
run pipe include user.

21
00:02:03,230 --> 00:02:11,270
Shows us that we have a user, David, and a user, Mary, with the relevant passwords, but to the

22
00:02:11,270 --> 00:02:14,630
local username and password database

23
00:02:15,710 --> 00:02:26,060
is only used if the Tacacs server is not available. So as an example, if I stop the Tacacs service on

24
00:02:26,060 --> 00:02:27,560
the Tacacs server

25
00:02:28,470 --> 00:02:40,950
and exit out of the router and then log in as David, I can access the broader so I can only use the

26
00:02:40,950 --> 00:02:45,510
local username and password database if the Tacacs server is down.

27
00:02:46,500 --> 00:02:50,400
If, however, the Tacacs server is up, so I'll start the service again.

28
00:02:53,120 --> 00:03:04,250
If I try and log back in as David notice authentication has failed and once again on the server, we

29
00:03:04,250 --> 00:03:07,860
can see that David failed the authentication.

30
00:03:08,810 --> 00:03:11,420
I can, however, log back in as admin.

31
00:03:13,090 --> 00:03:18,970
Now, what's really nice about this is that you can create a centralized user accounts so I could create

32
00:03:18,970 --> 00:03:22,990
a user called user one set to their password

33
00:03:25,770 --> 00:03:36,300
and click submit, so when I look at the available users, I now have a user called User One, and without

34
00:03:36,300 --> 00:03:45,990
making any configuration changes on the router, we can log in as user one so that user doesn't exist

35
00:03:46,410 --> 00:03:51,090
in the local router configuration but exists on the Tacacs server.

36
00:03:51,900 --> 00:03:56,370
If I want to I can disable the user account.

37
00:03:56,970 --> 00:04:00,840
So user 1 is now disabled back on the router. 

38
00:04:01,800 --> 00:04:03,450
If we try and log in as user 1

39
00:04:04,710 --> 00:04:11,990
authentication has failed, and once again, looking at the reports on the ACS server.

40
00:04:13,030 --> 00:04:20,860
We can see failed attempts, user 1 account is disabled, so when they try to access this device,

41
00:04:21,430 --> 00:04:22,530
TTY 0,

42
00:04:22,570 --> 00:04:23,740
in other words, the console.

43
00:04:25,000 --> 00:04:26,830
Their login has failed.

44
00:04:27,770 --> 00:04:36,290
If they try to access that router remotely, so they try to Telnet the router and login as user 1,

45
00:04:37,250 --> 00:04:44,110
authentication has failed and refreshing the information on the tacacs server, we can see that user

46
00:04:44,110 --> 00:04:51,430
1 has failed, the authentication account is disabled and they try to access TTY 98.

47
00:04:51,490 --> 00:04:57,580
In other words, one of the VTY lines on the router, we're getting a lot of central information

48
00:04:57,820 --> 00:04:59,410
from the ACS server.

49
00:05:00,290 --> 00:05:02,980
What we can also do is enable some debugging.

50
00:05:06,880 --> 00:05:12,280
So login as admin and then we can use command such as Debug Tacacs

51
00:05:13,840 --> 00:05:17,980
and I'll just enable all of it and debug triple A

52
00:05:21,790 --> 00:05:23,680
and in this case we'll enable authentication.

53
00:05:24,910 --> 00:05:31,510
So when the user tries to access the router, we can see quite a bit of information.

54
00:05:32,530 --> 00:05:40,120
So AAA authentication log in, the users trying to log in, we using the default method note on the

55
00:05:40,610 --> 00:05:41,500
VTY lines.

56
00:05:44,290 --> 00:05:46,660
No authentication methods have been set.

57
00:05:47,580 --> 00:05:51,990
It's inheriting the default method, so default is being used.

58
00:05:53,560 --> 00:05:55,480
authentication start packet created.

59
00:05:56,460 --> 00:06:01,500
We're trying to get a response from the user in this case, the user took too long, so let's try that

60
00:06:01,500 --> 00:06:01,910
again.

61
00:06:05,610 --> 00:06:07,500
I'll put in the username of user 1.

62
00:06:10,040 --> 00:06:13,550
So we can see now it's asking for a password

63
00:06:18,650 --> 00:06:21,290
and notice the response failed.

64
00:06:22,330 --> 00:06:28,970
The server 10.111 has rejected that username, so let's put some spaces there and login with

65
00:06:28,970 --> 00:06:29,320
the

66
00:06:30,640 --> 00:06:31,510
admin user.

67
00:06:33,180 --> 00:06:34,200
Login succeeded.

68
00:06:35,460 --> 00:06:40,890
So in this case, we received a response of pass authentication succeeded.

69
00:06:41,930 --> 00:06:45,230
So go through the full process again.

70
00:06:48,150 --> 00:06:49,410
Telnet to the router.

71
00:06:50,880 --> 00:06:59,790
Default list is being used, we are asking for the user account, so that's admin asking for the password.

72
00:07:02,340 --> 00:07:03,990
Authentication succeeded.

73
00:07:04,950 --> 00:07:08,340
So we can see what's taking place in the background here.

74
00:07:09,460 --> 00:07:10,980
AAA authentication is being used.

75
00:07:16,310 --> 00:07:22,460
The router is told by the AAA server to ask the user for the username and then to ask them for their

76
00:07:22,460 --> 00:07:29,630
password and then to tell the user that they succeeded the authentication and can login.

77
00:07:30,080 --> 00:07:34,550
So that's an example of basic authentication on router 1.

78
00:07:35,570 --> 00:07:40,850
Now, there are two ways to set this up, we're using the older method at the moment because these routers

79
00:07:40,850 --> 00:07:44,480
don't support the newer method where we create a group.

80
00:07:44,480 --> 00:07:45,770
So I'll show you that in a moment.

81
00:07:46,250 --> 00:07:52,910
But before I do that, I'll copy this configuration to router 2, to show you that we can create

82
00:07:52,910 --> 00:07:55,370
a central authentication server.

83
00:07:59,060 --> 00:08:06,660
At the moment, we haven't configured router 2 on the ACS server, so we can still log in as David.

84
00:08:08,020 --> 00:08:14,890
So under network configuration, we need to create an entry for router 2, so router 2 10.1.2

85
00:08:14,890 --> 00:08:19,840
02  is the IP address of the router, show IP Interface brief.

86
00:08:21,360 --> 00:08:22,680
So there's the IP address.

87
00:08:24,410 --> 00:08:30,740
Key used is going to be Cisco and I'm going to click, submit and apply so that router is now being configured.

88
00:08:33,250 --> 00:08:34,510
So try and log in

89
00:08:35,820 --> 00:08:36,630
as David.

90
00:08:38,570 --> 00:08:46,550
Authentication has failed, try and login as admin authentication passes, we've now configured two routers

91
00:08:46,550 --> 00:08:48,440
with centralized authentication.

92
00:08:49,380 --> 00:08:52,410
Under the reports, failed attempts.

93
00:08:54,070 --> 00:09:01,480
We can see that David failed the authentication attempt on the second router, so we seek information

94
00:09:01,480 --> 00:09:06,110
for both router 2 and router 1, let's configure router 3.

95
00:09:06,820 --> 00:09:11,080
I'll take this configuration and paste it into router 3.

96
00:09:14,640 --> 00:09:23,160
On router 3, we can log in as David, so that works, but we can't log in as admin because we still

97
00:09:23,160 --> 00:09:24,960
need to configure the ACS server.

98
00:09:28,510 --> 00:09:38,740
So back on ACS, we'll add router 3 IP address is 10.1.1.203 password or keys, Cisco click

99
00:09:38,740 --> 00:09:40,900
submit the routers now configured.

100
00:09:42,390 --> 00:09:48,300
So previously, we couldn't log in as Admin but now hopefully we should be able to.

101
00:09:49,710 --> 00:09:50,750
Let's try again.

102
00:09:52,790 --> 00:09:53,930
David failed there.

103
00:09:55,710 --> 00:09:57,810
So Admin.

104
00:09:58,890 --> 00:10:00,600
So Admin Cisco works.

105
00:10:04,420 --> 00:10:07,420
David Cisco doesn't work.

106
00:10:08,460 --> 00:10:17,070
Because the router is now communicating with ACS, but Admin Cisco does, so we've now got three routers

107
00:10:17,070 --> 00:10:21,300
configured to communicate with an ACS server.

108
00:10:22,110 --> 00:10:25,440
These routers are using an older version of iOS.

109
00:10:26,990 --> 00:10:34,790
They're using version 12.4, and that version doesn't support Tacacs server groups, which is the

110
00:10:34,790 --> 00:10:38,230
new way of doing things and is what you need to know for the exam.

