Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
1
00:00:00,630 --> 00:00:02,160
When it comes to networking,
2
2
00:00:02,160 --> 00:00:05,883
you've probably heard of the term MAC address a lot.
3
3
00:00:06,740 --> 00:00:08,060
So in this lecture,
4
4
00:00:08,060 --> 00:00:10,820
I'm gonna cover what do we mean by MAC address,
5
5
00:00:10,820 --> 00:00:13,993
what it's used for, and how to change it.
6
6
00:00:13,993 --> 00:00:15,632
(dramatic music)
7
7
00:00:15,632 --> 00:00:18,215
(loud banging)
8
8
00:00:20,100 --> 00:00:23,550
MAC address stands for Media Access Control,
9
9
00:00:23,550 --> 00:00:26,850
it's a permanent, physical, and unique address
10
10
00:00:26,850 --> 00:00:29,170
assigned to network interfaces
11
11
00:00:29,170 --> 00:00:31,590
by the device manufacturer.
12
12
00:00:31,590 --> 00:00:33,560
So whether you have a wireless card,
13
13
00:00:33,560 --> 00:00:35,990
or a wired, or Ethernet card,
14
14
00:00:35,990 --> 00:00:38,000
each one of these network cards
15
15
00:00:38,000 --> 00:00:41,960
come with a specific address that is unique to this card.
16
16
00:00:41,960 --> 00:00:44,490
So there is no two devices in the world
17
17
00:00:44,490 --> 00:00:46,690
that would have the same MAC address.
18
18
00:00:46,690 --> 00:00:49,970
And this address will always be the same
19
19
00:00:49,970 --> 00:00:51,720
to this specific device,
20
20
00:00:51,720 --> 00:00:54,040
even if you unplug it from your computer,
21
21
00:00:54,040 --> 00:00:55,890
connect it to another computer,
22
22
00:00:55,890 --> 00:01:00,343
then this network device will always have the same address.
23
23
00:01:01,570 --> 00:01:04,160
So you might already know that the IP address
24
24
00:01:04,160 --> 00:01:08,070
is used in the internet to identify computers,
25
25
00:01:08,070 --> 00:01:11,900
and communicate between devices on the internet.
26
26
00:01:11,900 --> 00:01:14,850
The MAC address is used within the network
27
27
00:01:14,850 --> 00:01:19,423
to identify devices and transfer data between devices.
28
28
00:01:20,360 --> 00:01:22,730
So each piece of data or packet
29
29
00:01:22,730 --> 00:01:24,660
that is sent within the network
30
30
00:01:24,660 --> 00:01:28,900
contains a source MAC and a destination MAC.
31
31
00:01:28,900 --> 00:01:31,120
Therefore, this packet would flow
32
32
00:01:31,120 --> 00:01:33,863
from the source MAC to the destination MAC.
33
33
00:01:35,010 --> 00:01:38,440
So because this is a physical unique address
34
34
00:01:38,440 --> 00:01:41,710
to each interface, to each network device,
35
35
00:01:41,710 --> 00:01:45,010
and because it is used to identify devices,
36
36
00:01:45,010 --> 00:01:48,673
then changing it will make you anonymous on the network.
37
37
00:01:49,670 --> 00:01:52,460
Not only that, but the MAC address is often used
38
38
00:01:52,460 --> 00:01:55,660
by filters to prevent or allow devices
39
39
00:01:55,660 --> 00:01:57,160
to connect to networks,
40
40
00:01:57,160 --> 00:02:00,040
and do specific tasks on the network.
41
41
00:02:00,040 --> 00:02:02,080
So being able to change your MAC address
42
42
00:02:02,080 --> 00:02:04,080
to another device's MAC address
43
43
00:02:04,080 --> 00:02:06,870
will allow you to impersonate this device
44
44
00:02:06,870 --> 00:02:08,830
and allow you to do things
45
45
00:02:08,830 --> 00:02:11,040
that you might not be able to do.
46
46
00:02:11,040 --> 00:02:13,280
So you'd be able to bypass filters,
47
47
00:02:13,280 --> 00:02:16,450
or connect to networks that only specific devices
48
48
00:02:16,450 --> 00:02:19,290
with specific MAC addresses can connect to,
49
49
00:02:19,290 --> 00:02:22,333
and you will also be able to hide your identity.
50
50
00:02:23,500 --> 00:02:26,300
Now changing the MAC address is very, very simple,
51
51
00:02:26,300 --> 00:02:28,313
so let me show you how to do that.
52
52
00:02:29,530 --> 00:02:33,540
First of all, I'm going to use the ifconfig command
53
53
00:02:33,540 --> 00:02:36,250
to list all the network interfaces
54
54
00:02:36,250 --> 00:02:38,783
available on my Kali machine.
55
55
00:02:39,890 --> 00:02:43,540
What I mean by network interface is any device
56
56
00:02:43,540 --> 00:02:46,360
that allow us to connect to a network.
57
57
00:02:46,360 --> 00:02:48,610
So an example is a Wi-Fi card,
58
58
00:02:48,610 --> 00:02:51,223
or an Ethernet card, and so on.
59
59
00:02:52,450 --> 00:02:56,030
So you can see first of all we have eth0,
60
60
00:02:56,030 --> 00:03:00,750
and this is a virtual interface created by virtual box
61
61
00:03:00,750 --> 00:03:03,993
when we set Kali to use iNet network.
62
62
00:03:04,850 --> 00:03:08,890
So you can see the interface name is eth0,
63
63
00:03:08,890 --> 00:03:11,990
you can see it has an IP address because like I said,
64
64
00:03:11,990 --> 00:03:13,780
it's connected to a network.
65
65
00:03:13,780 --> 00:03:17,723
So if we go here, we can see it saying Wired Connected.
66
66
00:03:18,570 --> 00:03:22,350
So this is the interface that represents the wired network
67
67
00:03:22,350 --> 00:03:24,420
that Kali is connected to,
68
68
00:03:24,420 --> 00:03:26,803
which is actually a virtual NAT network.
69
69
00:03:27,790 --> 00:03:30,950
You can also see the netmask, the broadcast,
70
70
00:03:30,950 --> 00:03:34,030
and a really important piece of information,
71
71
00:03:34,030 --> 00:03:35,453
which is the ether.
72
72
00:03:36,320 --> 00:03:41,203
This is the MAC address of this virtual interface.
73
73
00:03:42,330 --> 00:03:44,150
Now, you can see similar information
74
74
00:03:44,150 --> 00:03:49,150
for my other two interfaces, the lo and the lan0.
75
75
00:03:49,370 --> 00:03:53,040
The only thing is you can see for both of these interfaces,
76
76
00:03:53,040 --> 00:03:56,210
we do not have an IP address.
77
77
00:03:56,210 --> 00:03:57,870
And the main reason for that
78
78
00:03:57,870 --> 00:04:00,670
is because none of these interfaces
79
79
00:04:00,670 --> 00:04:02,453
is connected to a network.
80
80
00:04:03,390 --> 00:04:07,780
Now lo is the default interface created by Linux,
81
81
00:04:07,780 --> 00:04:11,810
and lan0 is my real wireless adapter,
82
82
00:04:11,810 --> 00:04:15,710
so I can use it to connect to Wi-Fi networks.
83
83
00:04:15,710 --> 00:04:18,530
But if I go on the network in here,
84
84
00:04:18,530 --> 00:04:21,150
you'll see Wi-Fi is not connected,
85
85
00:04:21,150 --> 00:04:24,170
because I actually didn't connect to any network,
86
86
00:04:24,170 --> 00:04:27,723
and that's why it does not have an IP address.
87
87
00:04:29,420 --> 00:04:32,010
Now, this doesn't matter because what we want to do
88
88
00:04:32,010 --> 00:04:34,740
is to just change the MAC address,
89
89
00:04:34,740 --> 00:04:38,250
which again, is shown here under the ether part,
90
90
00:04:38,250 --> 00:04:41,863
so similar to what you're seeing here for eth0.
91
91
00:04:42,880 --> 00:04:45,960
Now, in order to change any of the values
92
92
00:04:45,960 --> 00:04:47,510
that you see in here,
93
93
00:04:47,510 --> 00:04:51,093
you have to first disable the interface.
94
94
00:04:52,120 --> 00:04:56,200
So in this example, we want to change the MAC address,
95
95
00:04:56,200 --> 00:04:58,820
so that is represented by the ether
96
96
00:04:58,820 --> 00:05:00,913
and the value is right here.
97
97
00:05:01,880 --> 00:05:04,870
So in order to disable an interface,
98
98
00:05:04,870 --> 00:05:09,480
we're gonna do ifconfig followed by the interface name,
99
99
00:05:09,480 --> 00:05:14,480
which is lan0 in my example, followed by down to disable it.
100
100
00:05:15,670 --> 00:05:17,700
Now, if I hit Enter, you'll see
101
101
00:05:17,700 --> 00:05:19,730
the command runs with no errors,
102
102
00:05:19,730 --> 00:05:23,310
so it means that it got executed properly.
103
103
00:05:23,310 --> 00:05:25,320
And the next thing that we need to do,
104
104
00:05:25,320 --> 00:05:28,750
is to change the option that we want to change.
105
105
00:05:28,750 --> 00:05:31,910
And in this example, we want to change the ether,
106
106
00:05:31,910 --> 00:05:33,963
which is the MAC address.
107
107
00:05:34,800 --> 00:05:37,283
So first, we're gonna type ifconfig,
108
108
00:05:38,260 --> 00:05:41,350
we're gonna type the interface that we want to change,
109
109
00:05:41,350 --> 00:05:45,960
one of its options, then we're gonna type
110
110
00:05:45,960 --> 00:05:49,440
the option that we want to change.
111
111
00:05:49,440 --> 00:05:53,100
And what we want to change is the hardware address,
112
112
00:05:53,100 --> 00:05:56,323
so we're gonna do hw ether.
113
113
00:05:57,380 --> 00:05:59,420
Then we're gonna give it the address
114
114
00:05:59,420 --> 00:06:02,520
that we want to change the MAC address to.
115
115
00:06:02,520 --> 00:06:07,520
So for example, I'm gonna use 00:11:22:33:44:55.
116
116
00:06:10,840 --> 00:06:12,670
Very, very simple command,
117
117
00:06:12,670 --> 00:06:16,210
we're doing ifconfig lan0 to select the interface
118
118
00:06:16,210 --> 00:06:18,410
that we want to change its option,
119
119
00:06:18,410 --> 00:06:21,160
we wanna set the hardware address,
120
120
00:06:21,160 --> 00:06:25,670
and we wanna set this address to this specific address.
121
121
00:06:25,670 --> 00:06:27,810
So you can use any address that you want,
122
122
00:06:27,810 --> 00:06:30,370
following the same format shown here.
123
123
00:06:30,370 --> 00:06:33,963
Just make sure your address starts with 00.
124
124
00:06:34,930 --> 00:06:37,270
So I'm gonna hit Enter and again,
125
125
00:06:37,270 --> 00:06:39,020
we don't see any error messages,
126
126
00:06:39,020 --> 00:06:42,470
so it means the command got executed properly.
127
127
00:06:42,470 --> 00:06:46,560
And finally, we just need to enable the interface
128
128
00:06:46,560 --> 00:06:50,360
because we disabled it, by doing, ifconfig lan0 down,
129
129
00:06:50,360 --> 00:06:55,360
so we just need to do, ifconfig lan0 up, to enable it.
130
130
00:06:57,840 --> 00:06:59,881
Now the interface is enabled,
131
131
00:06:59,881 --> 00:07:02,393
and if we do ifconfig again,
132
132
00:07:03,650 --> 00:07:06,610
and look at the ether part in here,
133
133
00:07:06,610 --> 00:07:09,310
you can see that it is changed
134
134
00:07:09,310 --> 00:07:11,953
to the MAC address that we specified.
135
135
00:07:13,970 --> 00:07:16,840
Now, this is done, and your MAC address has changed.
136
136
00:07:16,840 --> 00:07:20,700
Now, you can go ahead and start using the interface
137
137
00:07:20,700 --> 00:07:23,700
and it'll appear to have this MAC address
138
138
00:07:23,700 --> 00:07:26,290
instead of its original MAC address.
139
139
00:07:26,290 --> 00:07:30,543
And like I said, this can be useful in so many scenarios.
140
140
00:07:32,050 --> 00:07:35,670
Now, keep in mind, the MAC address will revert back
141
141
00:07:35,670 --> 00:07:39,520
to the original one once you restart the computer,
142
142
00:07:39,520 --> 00:07:43,170
because we're only changing the MAC address in memory,
143
143
00:07:43,170 --> 00:07:47,070
we're not really changing the physical MAC address.
144
144
00:07:47,070 --> 00:07:49,970
But if your MAC address is resetting
145
145
00:07:49,970 --> 00:07:53,140
to the original one without restarting,
146
146
00:07:53,140 --> 00:07:54,840
then something is going wrong.
147
147
00:07:54,840 --> 00:07:58,240
And it's probably happening because your network manager
148
148
00:07:58,240 --> 00:08:00,970
is resetting the MAC address.
149
149
00:08:00,970 --> 00:08:03,130
Not everybody will face this issue,
150
150
00:08:03,130 --> 00:08:05,730
so I'm not gonna cover it in this lecture,
151
151
00:08:05,730 --> 00:08:07,520
but if you face this issue,
152
152
00:08:07,520 --> 00:08:10,360
if your MAC address goes back to the original one
153
153
00:08:10,360 --> 00:08:12,690
without restarting the computer,
154
154
00:08:12,690 --> 00:08:14,860
then check out the YouTube video
155
155
00:08:14,860 --> 00:08:16,950
in the resources of this lecture,
156
156
00:08:16,950 --> 00:08:19,543
it'll show you how to fix this issue.
13656
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.