1
00:00:00,000 --> 00:00:00,990
In this lesson,

2
00:00:00,990 --> 00:00:03,540
we're going to discuss discovery protocols.

3
00:00:03,540 --> 00:00:05,520
In today's complex network environments,

4
00:00:05,520 --> 00:00:07,560
we have to understand and manage the myriad

5
00:00:07,560 --> 00:00:09,030
of different connected devices

6
00:00:09,030 --> 00:00:10,770
that we have on those networks.

7
00:00:10,770 --> 00:00:12,270
By using discovery protocols,

8
00:00:12,270 --> 00:00:14,100
like the Link Layer Discovery Protocol

9
00:00:14,100 --> 00:00:15,960
and the Cisco Discovery Protocol,

10
00:00:15,960 --> 00:00:18,780
we're going to be able to simplify this task for ourselves.

11
00:00:18,780 --> 00:00:21,270
First, we have the Link Layer Discovery Protocol.

12
00:00:21,270 --> 00:00:24,720
The Link Layer Discovery Protocol, also known as LLDP,

13
00:00:24,720 --> 00:00:26,880
is an open standard protocol that was defined

14
00:00:26,880 --> 00:00:30,330
in the IEEE 802.1ab standard,

15
00:00:30,330 --> 00:00:32,850
and this open protocol allows devices on a network

16
00:00:32,850 --> 00:00:35,400
to advertise themselves and discover the information

17
00:00:35,400 --> 00:00:37,320
that there is about other devices,

18
00:00:37,320 --> 00:00:38,700
and this promotes interoperability

19
00:00:38,700 --> 00:00:40,950
across multiple different vendors.

20
00:00:40,950 --> 00:00:42,690
Now, by using LLDP,

21
00:00:42,690 --> 00:00:44,820
we're going to have essential details provided to us,

22
00:00:44,820 --> 00:00:47,880
such as the device's identification, its capabilities,

23
00:00:47,880 --> 00:00:49,230
its associated ports,

24
00:00:49,230 --> 00:00:50,880
and this also offers network administrators

25
00:00:50,880 --> 00:00:52,890
a clear view of the network topology

26
00:00:52,890 --> 00:00:55,620
and can help us to achieve effective network management.

27
00:00:55,620 --> 00:00:57,420
Now, the second protocol we have to talk about

28
00:00:57,420 --> 00:00:59,640
is the Cisco Discovery Protocol.

29
00:00:59,640 --> 00:01:02,820
Now, the Cisco Discovery Protocol, also known as CDP,

30
00:01:02,820 --> 00:01:05,190
is a proprietary protocol developed by Cisco,

31
00:01:05,190 --> 00:01:06,810
as its name implies,

32
00:01:06,810 --> 00:01:09,330
and the CDP is going to provide similar functionalities

33
00:01:09,330 --> 00:01:12,090
that we can use just like LLDP,

34
00:01:12,090 --> 00:01:14,250
but the difference is they are specifically tailored

35
00:01:14,250 --> 00:01:16,500
for use in Cisco-based environments,

36
00:01:16,500 --> 00:01:18,270
including routing and switching devices

37
00:01:18,270 --> 00:01:20,010
that were made by Cisco.

38
00:01:20,010 --> 00:01:22,350
When you're dealing with the Cisco Discovery Protocol,

39
00:01:22,350 --> 00:01:23,580
it's going to facilitate the collection

40
00:01:23,580 --> 00:01:24,960
of detailed device information,

41
00:01:24,960 --> 00:01:26,640
including things like model numbers,

42
00:01:26,640 --> 00:01:28,740
IP addresses, connected interfaces,

43
00:01:28,740 --> 00:01:30,870
and even the device's power consumption.

44
00:01:30,870 --> 00:01:32,790
This information is much more detailed

45
00:01:32,790 --> 00:01:34,470
and much more valuable to us

46
00:01:34,470 --> 00:01:37,020
when we're operating in a Cisco-centric network

47
00:01:37,020 --> 00:01:39,210
because we now have this proprietary protocol

48
00:01:39,210 --> 00:01:41,580
that understands how to talk better to these devices

49
00:01:41,580 --> 00:01:45,660
than the open source and non-proprietary LLDP.

50
00:01:45,660 --> 00:01:47,520
Now, when you're using the CDP,

51
00:01:47,520 --> 00:01:49,980
it's important to realize that the specifics of each device

52
00:01:49,980 --> 00:01:51,990
can lead to a more optimized performance

53
00:01:51,990 --> 00:01:53,790
and swifter troubleshooting for you,

54
00:01:53,790 --> 00:01:55,830
which is why if you're running a Cisco network,

55
00:01:55,830 --> 00:01:59,250
you'll probably want to use CDP over LLDP.

56
00:01:59,250 --> 00:02:02,670
Now, both LLDP and CDP are considered instrumental

57
00:02:02,670 --> 00:02:04,980
in maintaining an accurate and comprehensive inventory

58
00:02:04,980 --> 00:02:06,720
of your network devices.

59
00:02:06,720 --> 00:02:08,100
This is because this inventory

60
00:02:08,100 --> 00:02:10,259
is not just going to be a list of connected devices,

61
00:02:10,259 --> 00:02:12,240
but it's actually going to be a dynamic and updating

62
00:02:12,240 --> 00:02:14,610
environment that provides a rich data set

63
00:02:14,610 --> 00:02:17,040
with insights into how these devices are interconnected

64
00:02:17,040 --> 00:02:19,350
and how data is flowing through our networks.

65
00:02:19,350 --> 00:02:21,960
This kind of visibility is not just convenient for us,

66
00:02:21,960 --> 00:02:22,793
but it's also necessary for us

67
00:02:22,793 --> 00:02:25,860
to be able to ensure network security, network performance,

68
00:02:25,860 --> 00:02:28,290
and network reliability over time.

69
00:02:28,290 --> 00:02:29,880
Now, when it comes to security,

70
00:02:29,880 --> 00:02:32,580
these two protocols do help us in quickly identifying

71
00:02:32,580 --> 00:02:35,160
any kind of unauthorized devices or rogue devices

72
00:02:35,160 --> 00:02:36,960
that may try to join our network.

73
00:02:36,960 --> 00:02:39,270
By having a real-time view of our connected devices,

74
00:02:39,270 --> 00:02:41,130
we're going to be able to spot any kind of anomalies

75
00:02:41,130 --> 00:02:42,660
and then take immediate action,

76
00:02:42,660 --> 00:02:44,700
which can then mitigate potential security threats

77
00:02:44,700 --> 00:02:46,770
for us much more quickly.

78
00:02:46,770 --> 00:02:49,644
Another great use for the information provided by LLDP

79
00:02:49,644 --> 00:02:53,520
and CDP is to be able to conduct performance optimization.

80
00:02:53,520 --> 00:02:55,470
When you're conducting performance optimization,

81
00:02:55,470 --> 00:02:57,900
we have to understand our network structures first

82
00:02:57,900 --> 00:02:59,970
because this allows for more informed decisions

83
00:02:59,970 --> 00:03:02,280
regarding how we want to better segment our network,

84
00:03:02,280 --> 00:03:03,780
how we want to conduct load balancing,

85
00:03:03,780 --> 00:03:06,750
and how we want to set up our quality of service settings too.

86
00:03:06,750 --> 00:03:09,390
Now, these protocols bring us lots of different benefits,

87
00:03:09,390 --> 00:03:10,440
like I just said,

88
00:03:10,440 --> 00:03:13,650
but they also require careful configuration and management.

89
00:03:13,650 --> 00:03:16,170
If you have the incorrect settings or misinterpretations

90
00:03:16,170 --> 00:03:17,730
of the data that you're receiving,

91
00:03:17,730 --> 00:03:19,470
this can actually lead to network issues

92
00:03:19,470 --> 00:03:21,540
or security vulnerabilities that could be exploited

93
00:03:21,540 --> 00:03:22,740
by an attacker.

94
00:03:22,740 --> 00:03:25,680
For example, if the Link Layer Discovery Protocol

95
00:03:25,680 --> 00:03:27,630
or the Cisco Discovery Protocol information

96
00:03:27,630 --> 00:03:29,940
is accessible over an unsecured port,

97
00:03:29,940 --> 00:03:31,410
this can actually provide an attacker

98
00:03:31,410 --> 00:03:33,450
with a roadmap of your entire network

99
00:03:33,450 --> 00:03:35,940
and essentially conduct a reconnaissance for them.

100
00:03:35,940 --> 00:03:37,590
Therefore, it's really important

101
00:03:37,590 --> 00:03:39,030
that you implement these protocols

102
00:03:39,030 --> 00:03:41,490
with a mindful approach that considers security

103
00:03:41,490 --> 00:03:43,110
as well as your overall environment

104
00:03:43,110 --> 00:03:44,220
to ensure that the information

105
00:03:44,220 --> 00:03:46,320
is only available to authorized personnel

106
00:03:46,320 --> 00:03:48,060
and authorized devices.

107
00:03:48,060 --> 00:03:51,660
So remember, when it comes to LLDP and CDP,

108
00:03:51,660 --> 00:03:53,790
these are more than just discovery protocols.

109
00:03:53,790 --> 00:03:55,410
They're also foundational tools

110
00:03:55,410 --> 00:03:57,930
for modern network management at scale.

111
00:03:57,930 --> 00:03:59,340
By providing us with a detailed view

112
00:03:59,340 --> 00:04:00,780
of the network's infrastructure,

113
00:04:00,780 --> 00:04:03,690
these two protocols can empower us as network administrators

114
00:04:03,690 --> 00:04:06,390
to better maintain, secure, and optimize our networks

115
00:04:06,390 --> 00:04:07,830
more effectively.

116
00:04:07,830 --> 00:04:10,530
As our networks continue to grow in size and complexity,

117
00:04:10,530 --> 00:04:12,330
the role of these type of discovery protocols

118
00:04:12,330 --> 00:04:14,640
in maintaining our network visibility and integrity

119
00:04:14,640 --> 00:04:16,620
becomes only more significant.

120
00:04:16,620 --> 00:04:19,110
So if you're using a multi-vendor environment,

121
00:04:19,110 --> 00:04:22,230
you can use LLDP, or the Link Layer Discovery Protocol,

122
00:04:22,230 --> 00:04:23,280
for this purpose.

123
00:04:23,280 --> 00:04:25,380
But if you're using a Cisco-only network,

124
00:04:25,380 --> 00:04:27,180
then you may want to opt to use CDP,

125
00:04:27,180 --> 00:04:29,040
or the Cisco Discovery Protocol,

126
00:04:29,040 --> 00:04:31,410
since it provides additional details and information

127
00:04:31,410 --> 00:04:33,213
that you don't get with LLDP.