1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
|
<html>
<head>
<meta charset="UTF-8">
<title>06 - preparation (isc_dhcp_live_boot)</title>
</head>
<body>
<h1 style="color:blue">06 - preparation (isc_dhcp_live_boot)</h1>
<h2>Kazalo</h2>
<ul>
<li><a href="#namen">Namen vaje</a></li>
<li><a href="#navidezniRacunalniki">Navidezni računalniki, ki so potrebni za izvedbo naloge</a></li>
<li><a href="#skicaPodomrezja">Skica našega podomrežja</a></li>
<li><a href="#simpleArbiterGW">Postavitev simpleArbiterGW</a></li>
<li><a href="#DHCP">Postavitev DHCP Server</a></li>
<li><a href="#clientA">Postavitev BootableClient A</a></li>
<li><a href="#clientB">Postavitev BootableClient B</a></li>
</ul>
<h2 id="namen">Namen vaje</h2>
<p>Kako narediti live boot z DHCP strežnikom.</p>
<h2 id="navidezniRacunalniki">Navidezni računalniki, ki so potrebni za izvedbo naloge</h2>
<p>Potrebujemo program VirtualBox ter naslednje 4 navidezne računalnike:
<ul>
<li><a href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterGW.vdi">simpleArbiterGW</a></li>
<li><a href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterDhcp.vdi">DHCP Server</a></li>
<li>Bootable Client A (računalnik brez diska)</li>
<li>Bootable Client B (računalnik brez diska)</li>
</ul>
</p>
<h2 id="skicaPodomrezja">Skica našega podomrežja</h2>
<img style="width: 800px; height: 610px;" src="../images/01.png" alt="slika-01"></img>
<p>Naš cilj je, da računalnik BootableClient A preko DHCP strežnika pridobil IP naslov ter se zažene z datoteko A, ki se nahaja na simpleArbiterGW,</br>če pa zaženemo računalnik BootableClient B pa si želimo, da ta preko DHCP strežnika pridobi IP naslov ter se zažene z nekim live ISO, ki se prav tako nahaja na simpleArbiterGW.
</p>
<h2 id="simpleArbiterGW">Postavitev <mark>simpleArbiterGW</mark></h2>
<p>Prenesemo <a href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterGW.vdi">simpleArbiterGW.vdi</a> ter zaženemo VirtualBox. Ko je datoteka prenesena v VirtualBoxu izberemo New ter v polje Name vpišemo simpleArbiterGW.</br>Ustrezno nastavimo tudi Memory size (1gb pomnilnika nam bo zadostovalo). Spodaj izberemo še "Use an existing virtual hard drive file" ter izberemo naš simpleArbiterGW.vdi in pritisnimo Create.</p>
</br>
<img style="width: 800px; height: 464px;" src="../images/02.png" alt="slika-02"></img>
<p>Nato zaženemo virtualni računalnik simpleArbiterGW ter se z uporabniškim imenom "root" ter geslom "kaboom" vpišemo v naš sistem.</br></br>
Prvo računalnik od NAT-a, kateri je vgrajen v VirtualBox dobi nek naslov (v našem primeru 10.0.2.15).</br>(Da to preverimo uporabimo ukaz <b>ifconfig</b>) Preko tega IP naslova in vmesnika eth0 smo povezani v internet.<p>
<img style="width: 800px; height: 384px;" src="../images/03.png" alt="slika-03"></img>
<p>Mi pa si želimo 2 omrežna vmesnika na tem računalniku! Enega bi radi imeli na NAT (tega že imamo) drugega pa na Internal Network,</br>preko katerega bomo komunicirali z DHCP Strežnikom ter ostalimi računalniki, ki bodo v našem Internal Network-u.</br></br>
Nov omrežni vmesnik dodamo tako, da ugasnemo naš virtualni računalnik, ter v VirtualBoxu označimo naš virtualni računalnik in pritisnemo na <b>Settings -> Network</b></br>
<b>Adapter</b> 1 imamo že nastavljeno na NAT, <b>Adapter 2</b> pa nastavimo na Internal Network</p>
<img style="width: 800px; height: 137px;" src="../images/04.png" alt="slika-04"></img>
<p>Tako, zdaj imamo nastavljena 2 vmesnika!</br>V VirtualBoxu lahko definiramo več Internal Networkov (notranjih omrežij) a za naše potrebe bo to dovolj. Shranimo nastavitve ter ponovno poženimo naš simpleArbiterGW.</br></br>
Zdaj moramo oba omrežna vmesnika nastaviti tako, da bosta imela nek naslov. Uredimo datoteko <b>interfaces</b> v imeniku
<b>/etc/network</b>.</p>
<img style="width: 800px; height: 229px;" src="../images/05.png" alt="slika-05"></img>
<p>Za eth0 je poskrbel že DHCP strežnik, ki je vgrajen v VirtualBox (na eth0 je določil nek IP).</br>
Mi moramo nastaviti še drugi mrežni vmesnik. Kako se imenuje iz glave ne vemo zato s pomočjo ukaza <b>ifconfig -a</b> pogledamo.</p>
<img style="width: 800px; height: 117px;" src="../images/06.png" alt="slika-06"></img>
<p>Ugotovimo da je ime vmesnika eth1.
Zdaj bi rad na eth1 nastavil en IP naslov.</br>
Lahko bi nastavil z ifconfig, a ko rebootaš računalnik se nastavitve ne ohranijo. To nebi radi!</br>
Pojdimo raje skonfigurirat nastavitve v <b>/etc/network/interfaces</b></br></br>
Izmislimo si eno naključno lokalno omrežje oz naslov lokalnega omrežja ter nastavimo eth1.
</p>
<img style="width: 800px; height: 296px;" src="../images/07.png" alt="slika-07"></img>
<p>Shranimo konfiguracijsko datoteko. Moj računalnik še nima IP-ja na eth1 zato uporabim ukaz <b>ifup eth1</b></p>
<img style="width: 800px; height: 23px;" src="../images/08.png" alt="slika-08"></img></br>
<p>Sedaj uporabimo ukaz <b>ifconfig</b>, da vidimo če imamo slučajno ip na vmesniku eth1</p>
<img style="width: 800px; height: 389px;" src="../images/09.png" alt="slika-09"></img>
<p>Vidim, da ip imam. Super! Gremo postavit DHCP Server!</p>
<h2 id="DHCP">Postavitev <mark>DHCP Server</mark></h2>
<p>Prenesemo <a href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterDhcp.vdi">simpleArbiterDhcp.vdi</a> ter zaženemo VirtualBox. Ko je datoteka prenesena v VirtualBoxu izberemo New ter v polje Name vpišemo DHCP Server.</br>Ustrezno nastavimo tudi Memory size (1gb pomnilnika nam bo zadostovalo). Spodaj izberemo še "Use an existing virtual hard drive file" ter izberemo naš simpleArbiterDhcp in pritisnimo Create.<br>Ustrezno nastavimo tudi nastavitve mreže iz NAT na Internal Network</p>
</br>
<img style="width: 800px; height: 464px;" src="../images/10.png" alt="slika-10"></img>
<p>Nato zaženemo virtualni računalnik DHCP Server ter se z uporabniškim imenom "root" ter geslom "kaboom" vpišemo v naš sistem.</br></br>
<p>Sprva naš računalnik nima nobenega ip-ja saj mu ga nismo nastavili! Pojdimo skonfigurirat nastavitve v <b>/etc/network/interfaces</b>.</br>Ampak kateri vmesnik sploh konfiguriramo? Z ukazom <b>ifconfig -a</b> ugotovimo da je to <b>eth0</b>.<br>
Spet si izberemo nek svoj statičen ip naslov.</p>
<img style="width: 800px; height: 283px;" src="../images/11.png" alt="slika-11"></img>
<p>Shranimo konfiguracijsko datoteko. Moj računalnik še nima IP-ja na eth0 zato uporabim ukaz <b>ifdown eth0</b> ter nato še <b>ifup eth0</b></p>
<img style="width: 800px; height: 25px;" src="../images/12.png" alt="slika-12"></img>
<p>Sedaj uporabimo ukaz <b>ifconfig</b>, da vidimo če imamo slučajno ip na vmesniku eth0</p>
<img style="width: 800px; height: 329px;" src="../images/13.png" alt="slika-13"></img>
<p>Hura imamo! Namestimo naš DHCP strežnik z ukazom <b>apt-get install isc-dhcp-server</b></p>
<img style="width: 800px; height: 322px;" src="../images/14.png" alt="slika-14"></img>
<p>Vidimo, da dobimo cel kup napak. Ampak zakaj? Zato, ker nimamo dostopa do interneta! <br>
Vmesniku eth0 moramo seveda povedati Gateway. Naš Gateway bo seveda IP našega simpleArbiter navideznega računalnika.</br> To naredimo s pomočjo ukaza <b>route add default gw 192.168.251.1 eth0</b></p>
<img style="width: 800px; height: 43px;" src="../images/15.png" alt="slika-15"></img>
<p>Probajmo ping-ati Googlov DNS strežnik, da ugotovimo če imamo sedaj internet.</br>
To naredimo z ukazom <b>ping 8.8.8.8</b>.</p>
<img style="width: 800px; height: 361px;" src="../images/16.png" alt="slika-16"></img>
<p>Googlov DNS strežnik se odziva, super! </br>
Ampak <b>apt-get install isc-dhcp-server</b> še vedno ne moremo naložiti.</br>
Začasno dodajmo še en mrežni vmesnik ter ga nastavimo na NAT, nato bomo dobili dostop do interneta ter lahko namestimo naš DHCP strežnik.</br></br>
Nov omrežni vmesnik dodamo tako, da ugasnemo naš virtualni računalnik, ter v VirtualBoxu označimo naš virtualni računalnik in pritisnemo na <b>Settings -> Network</b></br>
<b>Adapter 1</b> imamo že nastavljeno na Internal Network, <b>Adapter 2</b> pa nastavimo na NAT</p>
<img style="width: 800px; height: 134px;" src="../images/17.png" alt="slika-17"></img>
<p>Zaženemo naš DHCP Server in v <b>/etc/network/interfaces</b> začasno na koncu dodamo vrstico <b>iface eth1 inet dhcp</b>,datoteko shranimo ter poženemo ukaz <b>ifup eth1</b>.<br>
Sedaj imamo dostop do interneta in lahko namestimo naš DHCP strežnik z ukazom <b>apt-get install isc-dhcp-server install</b></br>
<img style="width: 800px; height: 26px;" src="../images/18.png" alt="slika-18"></img></br>
<p>Poglejmo kaj je v <b>/var/log/syslog</b>, to je datoteka kamor se shranjujejo sporočila kaj se dogaja v našem sistemu</p>
<img style="width: 800px; height: 323px;" src="../images/19.png" alt="slika-19"></img></br>
<p>Očitno moramo nastaviti dhcp strežnik ter mu povedati tudi kam naj posluša! </br>
Za nastavitve DHCP strežnika imamo <b>/etc/dhcp/dhcpd.conf</b>. Nastavimo jo! </br>
Prvo zakomentiramo <b>option domain-name-servers</b> zaradi tega da nebo napak da jih ne najde.</p>
<img style="width: 800px; height: 26px;" src="../images/20.png" alt="slika-20"></img></br>
<p>Nato skonfiguriramo dhcp strežnik, da bo serviral ip-je na nekem podomrežju. Dodamo naslednje zapise:</p>
<img style="width: 800px; height: 417px;" src="../images/21.png" alt="slika-21"></img>
<p><b>(subnet)</b> Nastavimo podomrežje ter območje naslovov od koder naj jih DHCP strežnik dodeli, katero datoteko naj servira,</br> poleg tega so eni PXE tako neumni, da če jim ti serviraš filename nevejo iz katerega serverja ga dobim, zato napišem še next-server </br>(ip od koder serviram, v našem primeru simpleArbiter), nastavim tudi gateway kateri je v našem primeru tudi simpleArbiter.</br></br>Ker bi radi, da v primeru zagona navideznega računalnika BootableClient B serviramo drugo datoteko, to naredimo tako da definiramo nek dodaten host na sledeč način:</br><b>(host special)</b> Pod <b>hardware ethernet</b> zapišemo MAC naslov našega BootableClient B katerega bo imel, dodelimo mu nek statičen ip naslov ter povemo še iz kje se naj datoteka <b>live-ISO</b> zažene.</p>
<p>Spremembe shranimo, ter ubijemo proces z imenom <b>dnsmasq</b> z ukazom <b>kilall dnsmasq</b>.</p>
<img style="width: 740px; height: 34px;" src="../images/22.png" alt="slika-22"></img>
<p>Sledi restart našega DHCP strežnika, da bo deloval z novimi nastavitvami, to naredimo z ukazom <b>service isc-dhcp-server restart</b></br>DHCP Strežnik je pripravljen! Pripravimo BootableClientA ter BootableClientB ter testirajmo!</p>
<h2 id="clientA">Postavitev <mark>BootableClient A</mark></h2>
<p>Odpremo VirtualBox ter izberemo <b>New</b> in pod <b>Name</b> napišemo BootableClient A ter pod <b>Hard drive</b> izberemo <b>Do not add a virtual hard drive</b> (saj si želimo računalnik brez diska), </br>in pritisnemo na gump Create, da se nam ustvari navidezni računalnik. Želimo, da bo računalnik priklopljen na Internal network zato označimo naš <b>Bootable Client A</b> ter pritisnimo na </br><b>Settings->Network</b> in prvi Adapter 1 spremenimo na Internal Network.</p>
<img style="width: 800px; height: 678px;" src="../images/23.png" alt="slika-23"></img>
<p>Želimo še, da se računalnik boot-a preko mreže, zato to nastavimo pod zavihkom <b>System</b></p> tako, da pod <b>Boot Order</b> obkljukamo samo <b>Network</b>.</br>
Nastavitve shranimo z pritiskom na gumb <b>OK</b></p>
<img style="width: 800px; height: 697px;" src="../images/24.png" alt="slika-24"></img>
<p>Poženemo našega BootableClient-a A in odličnoo, dobi ip naslov s pomočjo DHCP strežnika in simpleArbiter mu servira točno to datoteko katero si želimo <b>A.0</b></p>
<img style="width: 800px; height: 494px;" src="../images/25.png" alt="slika-25"></img>
<h2 id="clientB">Postavitev <mark>BootableClient B</mark></h2>
<p>Odpremo VirtualBox ter izberemo <b>New</b> in pod <b>Name</b> napišemo BootableClient B ter pod <b>Hard drive</b> izberemo <b>Do not add a virtual hard drive</b> (saj si želimo računalnik brez diska), </br>in pritisnemo na gump Create, da se nam ustvari navidezni računalnik. Želimo, da bo računalnik priklopljen na Internal network zato označimo naš <b>Bootable Client B</b> ter pritisnimo na </br><b>Settings->Network</b> in prvi Adapter 1 spremenimo na Internal Network.</br>
Poleg tega nastavimo še pod <b>MAC Address</b> takšen MAC naslov, kot ga imamo v nastavitvah DHCP strežnika (dhcpd.conf -> host special), saj želimo da bo ta naš računalnik izjema</br> in bo ob zagonu dobil drugo datoteko kot ostali in sicer <b>live-ISO</b></p>
<img style="width: 800px; height: 678px;" src="../images/26.png" alt="slika-26"></img>
<p>Želimo še, da se računalnik boot-a preko mreže, zato to nastavimo pod zavihkom <b>System</b></p> tako, da pod <b>Boot Order</b> obkljukamo samo <b>Network</b>.</br>
Nastavitve shranimo z pritiskom na gumb <b>OK</b></p>
<img style="width: 800px; height: 697px;" src="../images/27.png" alt="slika-27"></img>
<p>Poženemo našega BootableClient-a A in odličnoo, dobi ip naslov s pomočjo DHCP strežnika in simpleArbiter mu servira točno to datoteko katero si želimo <b>live-ISO</b></p>
<img style="width: 800px; height: 494px;" src="../images/28.png" alt="slika-28"></img>
</body>
</html>
<html>
<head>
<meta charset="UTF-8">
<title>06 - preparation (isc_dhcp_live_boot)</title>
</head>
<body>
<h1 style="color:blue">06 - preparation (isc_dhcp_live_boot)</h1>
<h2>Table of contents</h2>
<ul>
<li><a href="#namen">Purpose of this exercise</a></li>
<li><a href="#navidezniRacunalniki">Virtual machines, needed for the purpose of exercise</a></li>
<li><a
href="#skicaPodomrezja">Schematics of our subnet</a></li>
<li><a href="#simpleArbiterGW">Setting up simpleArbiterGW</a></li>
<li><a href="#DHCP">Setting up DHCP Server</a></li>
<li><a href="#clientA">Setting BootableClient A</a></li>
<li><a href="#clientB">Setting up BootableClient B</a></li>
</ul>
<h2 id="namen">Purpose of this exercise</h2>
<p>How to perform live boot using a DHCP server.</p>
<h2 id="navidezniRacunalniki">Virtual machines needed to perform the task.</h2>
<p>We need VirtualBox and the following 4 virtual
machines:
<ul>
<li><a href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterGW.vdi">simpleArbiterGW</a></li>
<li><a href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterDhcp.vdi">DHCP Server</a></li>
<li>Bootable Client A (diskless
machine)</li>
<li>Bootable Client B (diskless
machine)</li>
</ul>
</p>
<h2 id="skicaPodomrezja">Schematics of our subnet</h2>
<img style="width: 800px; height: 610px;" src="../images/01.png" alt="slika-01"></img>
<p>Our goal is to make BootableClient A get it's IP
through DHCP server and boot up using file
A, which is located on simpleArbiterGW,</br>If we run
BootableClient B machines, we would like it to retrieve it's IP
through DHCP server and boot from some live ISO which is also located on
SimpleArbiterGW.
</p>
<h2 id="simpleArbiterGW">Setting up <mark>simpleArbiterGW</mark></h2>
<p>Download <a
href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterGW.vdi">simpleArbiterGW.vdi</a>
and then run VirtualBox. After the file is downloaded, choose the New
option in VirtualBoxu and set simpleArbiterGW in the Name
field.</br>Memory size should be set accordingly (1gb will suffice). Then choose "Use an existing virtual hard drive file" and select simpleArbiterGW.vdi clicking Create.</p>
</br>
<img style="width: 800px; height: 464px;" src="../images/02.png" alt="slika-02"></img>
<p>We start our virtual machines simpleArbiterGW using the
following login
credentials; username: "root", password: "kaboom".</br></br>
At the start, the computer on NAt get's it's IP(in our case 10.0.2.15).</br>(to check this use<b>ifconfig</b>) We now use this address and eth0 interface to access the internet.<p>
<img style="width: 800px; height: 384px;" src="../images/03.png" alt="slika-03"></img>
<p>However, we would like this machine to have 2
interfaces! One on NAT(we already have this one), and the other one on Internal Network,</br>throuh which we will communicate wiht the DHCP Server and other machines on our Internal Network.</br></br>
We add a new interface, by turning off the virtual machine,
select our machine in VirtualBox and select
računalnik, ter v VirtualBoxu <b>Settings -> Network</b></br>
<b>Adapter</b> 1 is already set to NAT, we set <b>Adapter
2</b> to
Internal Network</p>
<img style="width: 800px; height: 137px;" src="../images/04.png" alt="slika-04"></img>
<p>So, now we have two network interfaces!</br>In VirtuaBox
we can define multiple Internal Networks, however, for our need's two
will suffice. We save the settings and restart simpleArbiterGW.</br></br>
What we must do now, is to assign both interfaces IP addresses. We do this by setting the<b>interfaces</b>file
located at<b>/etc/network</b>.</p>
<img style="width: 800px; height: 229px;" src="../images/05.png" alt="slika-05"></img>
<p>Eth0 was already handled by and integrated DHCP, so eth0 had been assigned an IP).</br>
We have to set up the other network interface. If we don't know it's name, we find it out using <b>ifconfig -a</b>.</p>
<img style="width: 800px; height: 117px;" src="../images/06.png" alt="slika-06"></img>
<p>We can conclude the interface names is set to Eth1.
Now we would like to assign an IP naslov to Eth1.</br>
Ifconfig could be used, but rebooting the machine would reset the settings. Which is not ideal :)</br>
So configuring <b>/etc/network/interfaces would be a better idea.</b></br></br>
Let's make up a random local network or a local area network or local area network address and assign it to eth1.
</p>
<img style="width: 800px; height: 296px;" src="../images/07.png" alt="slika-07"></img>
<p>We save the config file. Our machine still has no IP on eth1 so we use the <b>ifup eth1</b> command</p>
<img style="width: 800px; height: 23px;" src="../images/08.png" alt="slika-08"></img></br>
<p>Now we use the <b>ifconfig</b> command, to see whether and ip is assigned to eth1 interface</p>
<img style="width: 800px; height: 389px;" src="../images/09.png" alt="slika-09"></img>
<p>We can see the IP is set. Now let's set up the DHCP
Server!</p>
<h2 id="DHCP">Setting up <mark>DHCP Server</mark></h2>
<p>We download <a href="http://www.polz.si/media/uploads/kpov/virtualke/simpleArbiterDhcp.vdi">simpleArbiterDhcp.vdi</a> ter zaženemo VirtualBox. Ko je datoteka prenesena v VirtualBoxu izberemo New ter v polje Name vpišemo DHCP Server.</br>Ustrezno nastavimo tudi Memory size (1gb pomnilnika nam bo zadostovalo). Spodaj izberemo še "Use an existing virtual hard drive file" ter izberemo naš simpleArbiterDhcp in pritisnimo Create.</p>
</br>
<img style="width: 800px; height: 464px;" src="../images/10.png" alt="slika-10"></img>
<p>We run DHCP Server virtual machine and login using "root" ad username and "kaboom" as password.</br></br>
<p>At first, our machine has no assigned IP, since none was set! Let+s configure it in <b>/etc/network/interfaces</b>.</br>But which interface should we configure? Using <b>ifconfig -a</b> command, we see it's <b>eth0</b>interface.<br>
Again we select our IP address.</p>
<img style="width: 800px; height: 283px;" src="../images/11.png" alt="slika-11"></img>
<p>We save the configuration file. Our computer still has no IP address assigned to eth0, so using <b>ifdown eth0</b> and then <b>ifup eth0</b>we provide one.</p>
<img style="width: 800px; height: 25px;" src="../images/12.png" alt="slika-12"></img>
<p>Now let us use <b>ifconfig</b> command, to check whether there is an IP assigned to interface eth0</p>
<img style="width: 800px; height: 329px;" src="../images/13.png" alt="slika-13"></img>
<p>We got it! We install DHCP server using <b>apt-get install isc-dhcp-server</b></p>
<img style="width: 800px; height: 322px;" src="../images/14.png" alt="slika-14"></img>
<p>We see a bunch of errors. Why? Bacause, we have no internet access! <br>
We need to specify the Gateway for our inteface. Our Gateway bo seveda IP našega simpleArbiter navideznega računalnika.</br> To naredimo s pomočjo ukaza <b>route add default gw 192.168.251.1 eth0</b></p>
<img style="width: 800px; height: 43px;" src="../images/15.png" alt="slika-15"></img>
<p>Try pinging Google's DNS server at 8.8.8.8, to check if now have internet access.</br>
We do this using the <b>ping 8.8.8.8</b> command.</p>
<img style="width: 800px; height: 361px;" src="../images/16.png" alt="slika-16"></img>
<p>Google's DNS server is responding. Great! </br>
However, we still cannot run <b>apt-get install isc-dhcp-server</b></br>
Let's tempororly add another interface and set it to NAT, so we get internet access and install the DHCP server.</br></br>
We add a new interface by turning off the virtual computer, in VirtualBox we select our virtual machine and then select <b>Settings -> Network</b></br>
<b>Adapter 1</b> has already been set to Internal Network, we set <b>Adapter 2</b> to NAT</p>
<img style="width: 800px; height: 134px;" src="../images/17.png" alt="slika-17"></img>
<p>We run DHCP Server and in file<b>/etc/network/interfaces</b> at the end of the line add <b>iface eth1 inet dhcp</b>, then save the file and run <b>ifup eth1</b>.<br>
Now we have access to the internet and can install our DHCP server with <b>apt-get install isc-dhcp-server install</b> command</br>
<img style="width: 800px; height: 26px;" src="../images/18.png" alt="slika-18"></img></br>
<p>Let's see what's in<b>/var/log/syslog</b>, which is a file where our system information is stored in.</p>
<img style="width: 800px; height: 323px;" src="../images/19.png" alt="slika-19"></img></br>
<p>Looks like we need to set up a DHCP server and specify where it should listen! </br>
DHCP settings are stored in <b>/etc/dhcp/dhcpd.conf</b>. Let's set it! </br>
First let's comment out <b>option domain-name-servers</b> to avoid having errors.</p>
<img style="width: 800px; height: 26px;" src="../images/20.png" alt="slika-20"></img></br>
<p>Then we configure DHCP server, so it would serve IPs a a certain subnet. We add the following lines:</p>
<img style="width: 800px; height: 417px;" src="../images/21.png" alt="slika-21"></img>
<p><b>(subnet)</b> We set the subnet and the IP range, which the DHCP server should use, and which file it should serve.</p>Some PXEs are so unintelligent, that you should specify where they should get the files from and to do that you specify next-server </br>(IP from which it will be served from, in our case simpleArbiter), we also specify gateway, which, in our case is also simpleArbiter.</br></br>Ker bi radi, da v primeru zagona navideznega računalnika BootableClient B serviramo drugo datoteko, to naredimo tako da definiramo nek dodaten host na sledeč način:</br><b>(host special)</b> Pod <b>hardware ethernet</b> zapišemo MAC naslov našega BootableClient B katerega bo imel, dodelimo mu nek statičen ip naslov ter povemo še iz kje se naj datoteka <b>live-ISO</b> zažene.</p>
<p>We save the settings and kill terthe process with ubijemo named <b>dnsmasq</b>using<b>kilall dnsmasq</b>.</p>
<img style="width: 740px; height: 34px;" src="../images/22.png" alt="slika-22"></img>
<p>Sledi restart našega DHCP strežnika, da bo deloval z novimi nastavitvami, to naredimo z ukazom <b>service isc-dhcp-server restart</b></br>DHCP server is now ready! We supply BootableClientA and BootableClientB and test them!</p>
<h2 id="clientA">Postavitev <mark>BootableClient A</mark></h2>
<p>We open VirtualBox and select <b>New</b>, for the y
<b>Name</b> field we specify
BootableClient A and for the <b>Hard drive</b> we select <b>Do not add a
virtual
hard drive</b> (as we want diskless device), </br>and select Create.
We want the computer to be on Internal network so vse select our
<b>Bootable Client
A</b> and select </br><b>Settings->Network</b> where we change Adapter
1 to Internal Network.</p>
<img style="width: 800px; height: 678px;" src="../images/23.png" alt="slika-23"></img>
<p>We also wan our computer to boot through network, so
under<b>Boot Order</b>tab select <b>Network</b>.</br>
We save the setting by clicking <b>OK</b></p>
<img style="width: 800px; height: 697px;" src="../images/24.png" alt="slika-24"></img>
<p>We run our BootableClient-a A and it get's it's
IP(which is great), using the DHCP server and the simpleArbiter serves
it exactly the file we specified. <b>A.0</b></p>
<img style="width: 800px; height: 494px;" src="../images/25.png" alt="slika-25"></img>
<h2 id="clientB">Setting up<mark>BootableClient
B</mark></h2>
<p>Odpremo VirtualBox ter izberemo <b>New</b> in pod <b>Name</b> napišemo BootableClient B ter pod <b>Hard drive</b> izberemo <b>Do not add a virtual hard drive</b> (saj si želimo računalnik brez diska), </br>in pritisnemo na gump Create, da se nam ustvari navidezni računalnik. Želimo, da bo računalnik priklopljen na Internal network zato označimo naš <b>Bootable Client B</b> ter pritisnimo na </br><b>Settings->Network</b> in prvi Adapter 1 spremenimo na Internal Network.</br>
Poleg tega nastavimo še pod <b>MAC Address</b> takšen MAC naslov, kot ga imamo v nastavitvah DHCP strežnika (dhcpd.conf -> host special), saj želimo da bo ta naš računalnik izjema</br> in bo ob zagonu dobil drugo datoteko kot ostali in sicer <b>live-ISO</b></p>
<img style="width: 800px; height: 678px;" src="../images/26.png" alt="slika-26"></img>
<p>Želimo še, da se računalnik boot-a preko mreže, zato to nastavimo pod zavihkom <b>System</b></p> tako, da pod <b>Boot Order</b> obkljukamo samo <b>Network</b>.</br>
Nastavitve shranimo z pritiskom na gumb <b>OK</b></p>
<img style="width: 800px; height: 697px;" src="../images/27.png" alt="slika-27"></img>
<p>Poženemo našega BootableClient-a A in odličnoo, dobi ip naslov s pomočjo DHCP strežnika in simpleArbiter mu servira točno to datoteko katero si želimo <b>live-ISO</b></p>
<img style="width: 800px; height: 494px;" src="../images/28.png" alt="slika-28"></img>
</body>
</html>
|
