1 00:00:00,090 --> 00:00:01,440 At this point, you should be familiar 2 00:00:01,440 --> 00:00:04,230 with the basics of computer networking. 3 00:00:04,230 --> 00:00:05,790 In this demonstration, we're going to walk through 4 00:00:05,790 --> 00:00:07,230 how to configure, monitor, 5 00:00:07,230 --> 00:00:09,660 and manage network connections in Linux. 6 00:00:09,660 --> 00:00:12,371 We'll go over the network manager, utility, 7 00:00:12,371 --> 00:00:15,600 and we want to use commands such as, nmtui, 8 00:00:15,600 --> 00:00:18,180 the text-based user interface. 9 00:00:18,180 --> 00:00:20,409 We're going to go over nmcli, 10 00:00:20,409 --> 00:00:22,290 and also we're just going to use a GUI 11 00:00:22,290 --> 00:00:24,480 to configure some of the network configurations. 12 00:00:24,480 --> 00:00:26,943 So let's start with the nmcli command. 13 00:00:27,900 --> 00:00:30,453 So this command, we can use this general fixture. 14 00:00:31,380 --> 00:00:32,883 We got a host name here. 15 00:00:34,380 --> 00:00:37,113 It's going to tell us what the current host is. 16 00:00:38,730 --> 00:00:40,473 All right, we're going to also use 17 00:00:40,473 --> 00:00:43,560 the infamous hostname command. 18 00:00:43,560 --> 00:00:45,900 So gives the exact same information. 19 00:00:45,900 --> 00:00:47,500 There's a few ways to view that. 20 00:00:48,690 --> 00:00:50,040 Now, if we want to change this host name, 21 00:00:50,040 --> 00:00:54,873 we want to use the sudo hostname control. 22 00:00:56,130 --> 00:00:57,753 We want to set the host name. 23 00:01:01,890 --> 00:01:03,490 And we'll change it to server02. 24 00:01:04,958 --> 00:01:06,033 It was 01 earlier. 25 00:01:07,170 --> 00:01:08,310 Put a password in. 26 00:01:08,310 --> 00:01:10,680 All right, let's make sure that went through. 27 00:01:10,680 --> 00:01:12,633 Okay, see that quickly changed for us. 28 00:01:13,500 --> 00:01:15,300 One thing to know with any of these services, 29 00:01:15,300 --> 00:01:16,680 these changes aren't persistent. 30 00:01:16,680 --> 00:01:18,750 So in order for it to stay, we're going to have 31 00:01:18,750 --> 00:01:19,740 to restart the system. 32 00:01:19,740 --> 00:01:23,433 So let's do a system control. 33 00:01:27,510 --> 00:01:28,710 And we're going to restart. 34 00:01:32,550 --> 00:01:33,483 Systemd. 35 00:01:36,360 --> 00:01:38,163 Remember that from last time? 36 00:01:39,060 --> 00:01:40,953 hostnamed, service. 37 00:01:42,735 --> 00:01:45,720 So now all this means is the system will persist 38 00:01:45,720 --> 00:01:47,580 through any restarts. 39 00:01:47,580 --> 00:01:48,840 So now, instead of reverting back 40 00:01:48,840 --> 00:01:51,693 to server01, it'll stay at server02. 41 00:01:53,700 --> 00:01:54,543 Simple enough. 42 00:01:55,620 --> 00:01:59,670 Now, we're just going to go over really quick ifconfig. 43 00:01:59,670 --> 00:02:01,560 This has been a tried and true command 44 00:02:01,560 --> 00:02:03,060 throughout the Linux history, 45 00:02:03,060 --> 00:02:04,950 but it has been recently replaced. 46 00:02:04,950 --> 00:02:06,750 Now it can still be used, it's deprecated, 47 00:02:06,750 --> 00:02:08,130 so it's still usable, 48 00:02:08,130 --> 00:02:10,830 but it's been replaced with the ipcommand. 49 00:02:10,830 --> 00:02:13,020 So again, it just shows us basic information 50 00:02:13,020 --> 00:02:16,530 about our network, the name of our netdevice. 51 00:02:16,530 --> 00:02:21,123 We have our IP address, sub netmask, broadcast ID, 52 00:02:22,050 --> 00:02:26,250 IPv6 information, MAC address, 53 00:02:26,250 --> 00:02:28,500 pretty much everything you would need. 54 00:02:28,500 --> 00:02:33,090 But again, as times change, we change with them. 55 00:02:33,090 --> 00:02:35,790 And if you look at the manual, you will see, 56 00:02:35,790 --> 00:02:38,430 and this is before anything in the future, 57 00:02:38,430 --> 00:02:40,130 that this program is now obsolete. 58 00:02:41,550 --> 00:02:42,450 So we're going to quit out of there 59 00:02:42,450 --> 00:02:43,290 and we want to take his advice, 60 00:02:43,290 --> 00:02:46,833 we want to check out the IP address command. 61 00:02:50,640 --> 00:02:53,130 And you can see pretty much gives us similar information, 62 00:02:53,130 --> 00:02:54,900 slightly different format, 63 00:02:54,900 --> 00:02:57,420 but this is the new way of doing things. 64 00:02:57,420 --> 00:03:00,210 So for this distribution on Linux, the normal format 65 00:03:00,210 --> 00:03:04,597 for the naming convention of our netdevice is going to be enp. 66 00:03:06,060 --> 00:03:10,080 And then it's going to be whatever we determine zero or one, 67 00:03:10,080 --> 00:03:14,310 and then S, and then another number that we determine. 68 00:03:14,310 --> 00:03:16,410 So that's going to be the typical format. 69 00:03:16,410 --> 00:03:21,410 If you see about halfway down enp0s3, 70 00:03:21,510 --> 00:03:23,223 that's going to be our ethernet NIC. 71 00:03:24,060 --> 00:03:24,960 Next thing we want to do is go get 72 00:03:24,960 --> 00:03:27,390 some more detailed information specifically 73 00:03:27,390 --> 00:03:28,740 about that device. 74 00:03:28,740 --> 00:03:31,443 So enp0s3. 75 00:03:32,340 --> 00:03:34,410 Now, again, all it does is allow us 76 00:03:34,410 --> 00:03:37,920 to hone in directly on that NIC, 77 00:03:37,920 --> 00:03:41,274 so we can see all the information about it that we need 78 00:03:41,274 --> 00:03:43,620 without being cluttered with all the other information such 79 00:03:43,620 --> 00:03:47,290 as the bridges, wireless networks, loopbacks. 80 00:03:47,290 --> 00:03:49,320 Okay, again, we see we have the same type 81 00:03:49,320 --> 00:03:52,740 of basic information, the ethernet address 82 00:03:52,740 --> 00:03:57,723 which is the MAC address, IP address, IPv6 address, 83 00:03:59,040 --> 00:04:03,330 broadcast information gateways, et cetera. 84 00:04:03,330 --> 00:04:04,163 Next can go back 85 00:04:04,163 --> 00:04:07,560 to the network manager command line tool again 86 00:04:07,560 --> 00:04:08,490 and that's how I'm going to get 87 00:04:08,490 --> 00:04:10,803 some general status about it. 88 00:04:15,510 --> 00:04:18,000 It gives us the monitoring feature capability just 89 00:04:18,000 --> 00:04:22,140 to see how our networks are up or down, up or down. 90 00:04:22,140 --> 00:04:24,090 Cuz once you have a big complex network 91 00:04:24,090 --> 00:04:25,530 you're not going to always be 92 00:04:25,530 --> 00:04:28,980 in close proximity to these systems. 93 00:04:28,980 --> 00:04:30,660 So you can't look at the back of a router 94 00:04:30,660 --> 00:04:33,420 or not, to see if a link is down or up. 95 00:04:33,420 --> 00:04:35,250 This is going to be good to see 96 00:04:35,250 --> 00:04:37,263 the general statuses of our servers. 97 00:04:38,130 --> 00:04:39,540 Okay, another command we want to use is 98 00:04:39,540 --> 00:04:42,333 the nmcli connection command. 99 00:04:43,680 --> 00:04:45,000 Now that's going to give us more 100 00:04:45,000 --> 00:04:47,760 specific device type of information. 101 00:04:47,760 --> 00:04:52,760 So names, the UUID, the type, and the device name again. 102 00:04:54,150 --> 00:04:56,100 Now we can also disable 103 00:04:56,100 --> 00:05:00,300 and enable the devices by using the same tool. 104 00:05:00,300 --> 00:05:02,310 So we're going to try it out, really quick connection. 105 00:05:02,310 --> 00:05:04,080 We're going to bring it down. 106 00:05:04,080 --> 00:05:07,563 We're going to do the enp0s3. 107 00:05:09,450 --> 00:05:10,283 All right. 108 00:05:10,283 --> 00:05:11,430 We see we have that system message. 109 00:05:11,430 --> 00:05:13,830 Let's us know that was successfully deactivated. 110 00:05:15,600 --> 00:05:17,040 So let's check out this device status just 111 00:05:17,040 --> 00:05:19,733 to make sure it went through just for more information. 112 00:05:22,200 --> 00:05:23,033 All right. 113 00:05:23,970 --> 00:05:25,170 I like how it's highlighted. 114 00:05:25,170 --> 00:05:28,110 So it draws to our attention very quickly 115 00:05:28,110 --> 00:05:29,370 with the red, and let's us know 116 00:05:29,370 --> 00:05:33,390 that that device is now disconnected or in a down state. 117 00:05:33,390 --> 00:05:34,540 Let's bring it back up. 118 00:05:37,290 --> 00:05:38,700 Remember, I always make use of the up arrow 119 00:05:38,700 --> 00:05:39,663 whenever you can. 120 00:05:41,070 --> 00:05:41,903 All right. 121 00:05:41,903 --> 00:05:44,553 See, it's back activated, check the status back to green. 122 00:05:46,380 --> 00:05:47,366 Now, next thing we're going to do, 123 00:05:47,366 --> 00:05:48,390 we're going to configure the system 124 00:05:48,390 --> 00:05:50,010 with that static IP address, meaning 125 00:05:50,010 --> 00:05:52,890 that this is when we select manual version 126 00:05:52,890 --> 00:05:54,150 and we're not going to actually use 127 00:05:54,150 --> 00:05:56,253 the DHCP servers assigned to us. 128 00:05:57,720 --> 00:05:58,590 Okay, so we just want to look 129 00:05:58,590 --> 00:06:01,560 at this IP address right now and see what it is. 130 00:06:01,560 --> 00:06:03,330 Under inet. 131 00:06:03,330 --> 00:06:06,930 So we see it's 10.0.2.15. 132 00:06:06,930 --> 00:06:09,933 We want to change that to 10.0.2.101, 133 00:06:11,700 --> 00:06:13,300 just for demonstration purposes. 134 00:06:16,470 --> 00:06:19,773 So you going to do network manager command line, 135 00:06:21,390 --> 00:06:22,683 connection edit. 136 00:06:24,870 --> 00:06:26,223 We're going to using enp0. 137 00:06:29,036 --> 00:06:30,210 So we'll just type to help really quick just 138 00:06:30,210 --> 00:06:32,610 to see what commands are available. 139 00:06:32,610 --> 00:06:34,980 And we're going to focus on the set command. 140 00:06:34,980 --> 00:06:38,253 Again, just allows us to change the property value of that. 141 00:06:39,356 --> 00:06:41,967 We're going to set the IPv4 addresses. 142 00:06:47,880 --> 00:06:51,563 10.50.1.101. 143 00:06:58,060 --> 00:07:01,533 Okay, going to do a 24 slash slider. 144 00:07:02,370 --> 00:07:04,233 And we're going to click this to yes. 145 00:07:05,220 --> 00:07:06,320 Change this to manual. 146 00:07:07,320 --> 00:07:08,870 Okay, we're going to do save here. 147 00:07:10,240 --> 00:07:13,240 So we have that updated, and we're going to quit out of here 148 00:07:14,160 --> 00:07:17,730 Now again, after we change any configuration, 149 00:07:17,730 --> 00:07:19,650 we have to bring the device up and down. 150 00:07:19,650 --> 00:07:21,633 So I'm just going to do command line. 151 00:07:23,239 --> 00:07:24,489 Going to do connection down. 152 00:07:25,530 --> 00:07:26,363 Enp0s3. 153 00:07:28,950 --> 00:07:30,700 Now let's bring this thing back up. 154 00:07:35,333 --> 00:07:38,670 Okay, now this resets the device. 155 00:07:38,670 --> 00:07:40,403 I'll just make sure that went through. 156 00:07:43,050 --> 00:07:47,580 Now, if you look at the enp0s3, number two, 157 00:07:47,580 --> 00:07:49,860 you'll see that the inet address has 158 00:07:49,860 --> 00:07:53,853 changed to 10.50.1.101/24. 159 00:07:55,680 --> 00:07:57,830 Exactly as we typed it in the last command. 160 00:07:58,710 --> 00:07:59,847 Next thing we want to do, we want to configure 161 00:07:59,847 --> 00:08:04,230 the system to now use a DHCP. 162 00:08:04,230 --> 00:08:07,593 So dynamic host configuration protocol. 163 00:08:08,490 --> 00:08:09,330 And again, it's nothing more 164 00:08:09,330 --> 00:08:11,940 than a network management protocol using IP networks 165 00:08:11,940 --> 00:08:14,550 for automatically assigning IP addresses. 166 00:08:14,550 --> 00:08:15,690 Let's configure that really quick. 167 00:08:15,690 --> 00:08:18,900 And this time we're going to use the text base interface. 168 00:08:18,900 --> 00:08:21,000 So we're going to use network manager, 169 00:08:21,000 --> 00:08:25,083 text space, user interface. 170 00:08:27,900 --> 00:08:30,060 And so we're going to edit the connection really quick. 171 00:08:30,060 --> 00:08:35,059 We're going to go here, edit, and we're just going to tap here. 172 00:08:35,130 --> 00:08:37,679 You see how we change the configuration 173 00:08:37,679 --> 00:08:40,169 to manual when it accessed early on the screen 174 00:08:40,169 --> 00:08:41,003 we're just going to change it back 175 00:08:41,003 --> 00:08:44,433 to automatic again, that enables DHCP. 176 00:08:45,690 --> 00:08:46,990 So that was simple enough. 177 00:08:52,890 --> 00:08:54,273 I'm going to scroll down here. 178 00:08:56,970 --> 00:08:57,803 Click okay. 179 00:08:59,580 --> 00:09:03,633 And go back and quit. 180 00:09:05,100 --> 00:09:05,940 All right, now we should be able 181 00:09:05,940 --> 00:09:07,830 to check this information again, 182 00:09:07,830 --> 00:09:09,690 and you should be able to see 183 00:09:09,690 --> 00:09:12,540 that it's not changed to a new IP address. 184 00:09:12,540 --> 00:09:14,670 So when we go back to the IP address. 185 00:09:14,670 --> 00:09:19,470 We want to show the device, enp0s3. 186 00:09:19,470 --> 00:09:24,060 Now we see the device still has the manual IP address. 187 00:09:24,060 --> 00:09:25,710 Again, everything has to be reset 188 00:09:25,710 --> 00:09:27,660 for it to issue a new IP address. 189 00:09:27,660 --> 00:09:28,617 So we're going to bring the device down 190 00:09:28,617 --> 00:09:30,690 and we're going to bring it back up. 191 00:09:30,690 --> 00:09:33,140 But this time we're going to use the system control. 192 00:09:34,980 --> 00:09:36,580 We're going to restart the network. 193 00:09:39,810 --> 00:09:43,353 Tell the DHCP to reissue out some addresses. 194 00:09:45,780 --> 00:09:46,680 All right. 195 00:09:46,680 --> 00:09:48,300 So now let's go back to this again. 196 00:09:48,300 --> 00:09:50,193 See if this IP address has changed. 197 00:09:52,590 --> 00:09:57,480 And if you see below, it has added a new IP address, 198 00:09:57,480 --> 00:10:01,440 letting us know that it is the 10.0.2.15. 199 00:10:01,440 --> 00:10:03,030 That's what it was earlier. 200 00:10:03,030 --> 00:10:04,290 And if you see towards the end, 201 00:10:04,290 --> 00:10:05,940 you see dynamic, letting us know 202 00:10:05,940 --> 00:10:08,733 that that was generated by our DHCP server. 203 00:10:10,200 --> 00:10:12,480 Now another tool we can use to get more information 204 00:10:12,480 --> 00:10:15,270 about the NIC is going to be the ethtool command. 205 00:10:15,270 --> 00:10:17,310 And so what this is going to do is give us 206 00:10:17,310 --> 00:10:20,193 detailed information about the NIC itself. 207 00:10:21,480 --> 00:10:22,563 So let's see here. 208 00:10:23,700 --> 00:10:27,180 It's going to give us the information about the link modes. 209 00:10:27,180 --> 00:10:29,460 10baseT/Half 10baseT/Full, 210 00:10:29,460 --> 00:10:32,160 meaning that's the ethernet standard, right? 211 00:10:32,160 --> 00:10:34,890 And so that means for the 10baseT/Half, 212 00:10:34,890 --> 00:10:37,620 that means 10 megabits per second, at half duplex, 213 00:10:37,620 --> 00:10:41,070 meaning you going to send information one at a time. 214 00:10:41,070 --> 00:10:45,060 It also supports 10base, meaning 10 megabits per second 215 00:10:45,060 --> 00:10:48,330 at full duplex and a hundred and a thousand. 216 00:10:48,330 --> 00:10:49,710 So we get the picture there. 217 00:10:49,710 --> 00:10:51,240 So it supports multiple modes 218 00:10:51,240 --> 00:10:54,030 and not just stuck at one speed. 219 00:10:54,030 --> 00:10:56,760 Now we also look at, see the duplex, 220 00:10:56,760 --> 00:10:58,710 the current mode is in full. 221 00:10:58,710 --> 00:11:01,140 Right, and the speed is capped out at one gigabyte. 222 00:11:01,140 --> 00:11:05,580 So it gives us more specs about the NIC itself. 223 00:11:05,580 --> 00:11:08,096 So when we're trying to do performance analysis 224 00:11:08,096 --> 00:11:12,270 and increase speeds, we can see what we're working with. 225 00:11:12,270 --> 00:11:14,130 And the next folder that's going to be useful to look at. 226 00:11:14,130 --> 00:11:16,560 It's going to be the networking folder, 227 00:11:16,560 --> 00:11:18,810 and that's going to be under the etc/sys/config. 228 00:11:19,950 --> 00:11:21,483 We'll go to network scripts. 229 00:11:25,410 --> 00:11:29,010 Now this folder is useful because it shows a list 230 00:11:29,010 --> 00:11:32,430 of all of these scripts that will be ran at boot. 231 00:11:32,430 --> 00:11:34,770 These scripts will be ran to do a lot 232 00:11:34,770 --> 00:11:36,630 of the initial configuration settings. 233 00:11:36,630 --> 00:11:37,470 It'll set up things such 234 00:11:37,470 --> 00:11:42,300 as IP address, host names, gateways, et cetera. 235 00:11:42,300 --> 00:11:46,350 Now, to get specific to our particular NIC, 236 00:11:46,350 --> 00:11:47,650 we're going to look at the... 237 00:11:49,739 --> 00:11:53,460 The /etc/ and use this config. 238 00:11:53,460 --> 00:11:56,763 Course, I'm going to do the network scripts. 239 00:12:06,065 --> 00:12:09,510 Enp0s3. 240 00:12:09,510 --> 00:12:12,330 And again, more key device information as well 241 00:12:12,330 --> 00:12:14,700 as IP configuration information. 242 00:12:14,700 --> 00:12:18,330 So we can see that on boot, flag set to yes. 243 00:12:18,330 --> 00:12:22,110 We see the IP address, gateway prefix meaning 244 00:12:22,110 --> 00:12:24,840 whether that's going to be our mask or CIDR, 245 00:12:24,840 --> 00:12:27,900 and a lot of good information on this particular screen. 246 00:12:27,900 --> 00:12:30,480 All right, next we're just go ahead, do it another way. 247 00:12:30,480 --> 00:12:33,450 Just going to use the GUI to actually make 248 00:12:33,450 --> 00:12:35,490 the next configuration change so we can go 249 00:12:35,490 --> 00:12:38,043 to system tools here, we go to settings. 250 00:12:45,000 --> 00:12:45,833 Okay. 251 00:12:48,210 --> 00:12:50,253 Scroll down, go to network. 252 00:12:51,120 --> 00:12:51,953 All right. 253 00:12:51,953 --> 00:12:54,000 So we're going to hit the settings button right here. 254 00:12:54,000 --> 00:12:55,380 Now you see it still shows 255 00:12:55,380 --> 00:13:00,030 that we have the static IP address going on right here. 256 00:13:00,030 --> 00:13:02,220 So what we're going to do is we're going to turn 257 00:13:02,220 --> 00:13:03,970 this thing off and turn it back on. 258 00:13:06,405 --> 00:13:07,238 All right. 259 00:13:08,096 --> 00:13:13,096 Now we see we now have the DHCP selected 260 00:13:13,230 --> 00:13:15,183 IP address for us right here. 261 00:13:16,560 --> 00:13:19,980 Okay, we can also see that the method 262 00:13:19,980 --> 00:13:23,970 for IPv4 is automatically set here. 263 00:13:23,970 --> 00:13:26,250 Again, this configuration changes that went through 264 00:13:26,250 --> 00:13:28,263 from our text base interface. 265 00:13:29,310 --> 00:13:32,460 So we reset the network, so we can have the DHCP issue us 266 00:13:32,460 --> 00:13:35,130 new IP addresses, but we also still had to bring 267 00:13:35,130 --> 00:13:39,360 the link down and back up, so it could use it. 268 00:13:39,360 --> 00:13:42,150 Okay, so here we're going to do a little bit more practice. 269 00:13:42,150 --> 00:13:44,790 We're going to make this a manual IP address. 270 00:13:44,790 --> 00:13:47,910 And now I'm going to stay within the same subnet 271 00:13:47,910 --> 00:13:50,070 of the DNS server. 272 00:13:50,070 --> 00:13:51,630 I'm going to change the IP address. 273 00:13:51,630 --> 00:13:53,640 Just one up to what it was before. 274 00:13:53,640 --> 00:13:54,840 Keep the same gateway. 275 00:13:54,840 --> 00:13:56,880 We know that one works for us. 276 00:13:56,880 --> 00:13:58,683 And keep the same net mask. 277 00:13:59,580 --> 00:14:03,873 Have the DNS server as Google server 8.8.8.8. 278 00:14:05,880 --> 00:14:08,700 Going to just see how this works with the manual. 279 00:14:08,700 --> 00:14:09,700 Going to turn this off. 280 00:14:12,660 --> 00:14:13,950 So now we're going to go check and see 281 00:14:13,950 --> 00:14:17,733 if we can hit CompTIA's website from Firefox. 282 00:14:19,430 --> 00:14:23,914 Okay, let's do https. 283 00:14:23,914 --> 00:14:28,914 I'm going to go to comptia.org. 284 00:14:30,780 --> 00:14:31,613 All right. 285 00:14:31,613 --> 00:14:34,713 Looks like our connection is still working for us. 286 00:14:36,570 --> 00:14:38,310 Okay, we went through multiple ways 287 00:14:38,310 --> 00:14:43,310 of how to monitor, manage, and configure IP configurations. 288 00:14:43,650 --> 00:14:45,540 And again, how to view just general statuses 289 00:14:45,540 --> 00:14:49,680 of the system and how to view a few configuration statuses. 290 00:14:49,680 --> 00:14:50,940 Thank you for sticking with this lesson, 291 00:14:50,940 --> 00:14:52,590 and I'll see you in the next one.