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more updates for pppoe and bug 171584

1 <?xml version="1.0" encoding="UTF-8"?>
2 <!DOCTYPE sections SYSTEM "/dtd/book.dtd">
3
4 <!-- The content of this document is licensed under the CC-BY-SA license -->
5 <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
6
7 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-net-modules.xml,v 1.22 2007/04/08 01:28:11 nightmorph Exp $ -->
8
9 <sections>
10
11 <abstract>
12 Gentoo provides you flexible networking - here you are told about choosing
13 different DHCP clients, setting up bonding, bridging, VLANs and more.
14 </abstract>
15
16 <version>8.2</version>
17 <date>2007-04-13</date>
18
19 <section>
20 <title>Network Modules</title>
21 <body>
22
23 <p>
24 We now support modular networking scripts, which means we can easily add support
25 for new interface types and configuration modules while keeping compatibility
26 with existing ones.
27 </p>
28
29 <p>
30 Modules load by default if the package they need is installed. If you specify a
31 module here that doesn't have its package installed then you get an error
32 stating which package you need to install. Ideally, you only use the modules
33 setting when you have two or more packages installed that supply the same
34 service and you need to prefer one over the other.
35 </p>
36
37 <note>
38 All settings discussed here are stored in <path>/etc/conf.d/net</path> unless
39 otherwise specified.
40 </note>
41
42 <pre caption="Module preference">
43 <comment># Prefer iproute2 over ifconfig</comment>
44 modules=( "iproute2" )
45
46 <comment># You can also specify other modules for an interface
47 # In this case we prefer udhcpc over dhcpcd</comment>
48 modules_eth0=( "udhcpc" )
49
50 <comment># You can also specify which modules not to use - for example you may be
51 # using a supplicant or linux-wlan-ng to control wireless configuration but
52 # you still want to configure network settings per ESSID associated with.</comment>
53 modules=( "!iwconfig" )
54 </pre>
55
56 </body>
57 </section>
58 <section>
59 <title>Interface Handlers</title>
60 <body>
61
62 <p>
63 We provide two interface handlers presently: <c>ifconfig</c> and
64 <c>iproute2</c>. You need one of these to do any kind of network configuration.
65 </p>
66
67 <p>
68 <c>ifconfig</c> is the current Gentoo default and it's included in the system
69 profile. <c>iproute2</c> is a more powerful and flexible package, but it's not
70 included by default.
71 </p>
72
73 <pre caption="To install iproute2">
74 # <i>emerge sys-apps/iproute2</i>
75
76 <comment># To prefer iproute2 over ifconfig if both are installed</comment>
77 modules=( "iproute2" )
78 </pre>
79
80 <p>
81 As both <c>ifconfig</c> and <c>iproute2</c> do very similar things we allow
82 their basic configuration to work with each other. For example both the below
83 code snippet work regardless of which module you are using.
84 </p>
85
86 <pre caption="ifconfig and iproute2 examples">
87 config_eth0=( "192.168.0.2/24" )
88 config_eth0=( "192.168.0.2 netmask 255.255.255.0" )
89
90 <comment># We can also specify broadcast</comment>
91 config_eth0=( "192.168.0.2/24 brd 192.168.0.255" )
92 config_eth0=( "192.168.0.2 netmask 255.255.255.0 broadcast 192.168.0.255" )
93 </pre>
94
95 </body>
96 </section>
97 <section id="dhcp">
98 <title>DHCP</title>
99 <body>
100
101 <p>
102 DHCP is a means of obtaining network information (IP address, DNS servers,
103 Gateway, etc) from a DHCP server. This means that if there is a DHCP server
104 running on the network, you just have to tell each client to use DHCP and it
105 sets up the network all by itself. Of course, you will have to configure for
106 other things like wireless, PPP or other things if required before you can use
107 DHCP.
108 </p>
109
110 <p>
111 DHCP can be provided by <c>dhclient</c>, <c>dhcpcd</c>, <c>pump</c> or
112 <c>udhcpc</c>. Each DHCP module has its pros and cons - here's a quick run down.
113 </p>
114
115 <table>
116 <tr>
117 <th>DHCP Module</th>
118 <th>Package</th>
119 <th>Pros</th>
120 <th>Cons</th>
121 </tr>
122 <tr>
123 <ti><c>dhclient</c></ti>
124 <ti><c>net-misc/dhcp</c></ti>
125 <ti>
126 Made by ISC, the same people who make the BIND DNS software. Very
127 configurable
128 </ti>
129 <ti>
130 Configuration is overly complex, software is quite bloated, cannot get
131 NTP servers from DHCP, does not send hostname by default
132 </ti>
133 </tr>
134 <tr>
135 <ti><c>dhcpcd</c></ti>
136 <ti><c>net-misc/dhcpcd</c></ti>
137 <ti>
138 Long time Gentoo default, no reliance on outside tools, actively developed
139 by Gentoo
140 </ti>
141 <ti>Can be slow at times, does not yet daemonize when lease is infinite</ti>
142 </tr>
143 <tr>
144 <ti><c>pump</c></ti>
145 <ti><c>net-misc/pump</c></ti>
146 <ti>
147 Lightweight, no reliance on outside tools
148 </ti>
149 <ti>
150 No longer maintained upstream, unreliable, especially over modems, cannot
151 get NIS servers from DHCP
152 </ti>
153 </tr>
154 <tr>
155 <ti><c>udhcpc</c></ti>
156 <ti><c>net-misc/udhcp</c></ti>
157 <ti>
158 Lightweight - smallest DHCP client around, made for embedded systems
159 </ti>
160 <ti>
161 Unproven - no distro uses it by default, cannot define a timeout beyond 3
162 seconds
163 </ti>
164 </tr>
165 </table>
166
167 <p>
168 If you have more than one DHCP client installed, you need to specify which one
169 to use - otherwise we default to <c>dhcpcd</c> if available.
170 </p>
171
172 <p>
173 To send specific options to the DHCP module, use <c>module_eth0="..."</c>
174 <e>(change module to the DHCP module you're using - i.e. <c>dhcpcd_eth0</c>)</e>.
175 </p>
176
177 <p>
178 We try and make DHCP relatively agnostic - as such we support the following
179 commands using the <c>dhcp_eth0</c> variable. The default is not to set any of
180 them:
181 </p>
182
183 <ul>
184 <li><c>release</c> - releases the IP address for re-use</li>
185 <li><c>nodns</c> - don't overwrite <path>/etc/resolv.conf</path></li>
186 <li><c>nontp</c> - don't overwrite <path>/etc/ntp.conf</path></li>
187 <li><c>nonis</c> - don't overwrite <path>/etc/yp.conf</path></li>
188 </ul>
189
190 <pre caption="Sample DHCP configuration in /etc/conf.d/net">
191 <comment># Only needed if you have more than one DHCP module installed</comment>
192 modules=( "dhcpcd" )
193
194 config_eth0=( "dhcp" )
195 dhcpcd_eth0="-t 10" <comment># Timeout after 10 seconds</comment>
196 dhcp_eth0="release nodns nontp nonis" <comment># Only get an address</comment>
197 </pre>
198
199 <note>
200 <c>dhcpcd</c>, <c>udhcpc</c> and <c>pump</c> send the current hostname to the
201 DHCP server by default so you don't need to specify this anymore.
202 </note>
203
204 </body>
205 </section>
206 <section>
207 <title>ADSL with PPPoE/PPPoA</title>
208 <body>
209
210 <p>
211 First we need to install the ADSL software.
212 </p>
213
214 <pre caption="Install the ppp package">
215 # <i>emerge net-dialup/ppp</i>
216 </pre>
217
218 <note>
219 If you need PPPoA, then make sure to use >=<c>baselayout-1.12.x</c>.
220 </note>
221
222 <p>
223 Second, create the PPP net script and the net script for the ethernet interface
224 to be used by PPP:
225 </p>
226
227 <pre caption="Creating the PPP and ethernet scripts">
228 # <i>ln -s /etc/init.d/net.lo /etc/init.d/net.ppp0</i>
229 # <i>ln -s /etc/init.d/net.lo /etc/init.d/net.eth0</i>
230 </pre>
231
232 <p>
233 Be sure to set RC_NET_STRICT_CHECKING="yes" in <path>/etc/conf.d/rc</path>.
234 </p>
235
236 <p>
237 Now we need to configure <path>/etc/conf.d/net</path>.
238 </p>
239
240 <pre caption="A basic PPPoE setup">
241 config_eth0=( null ) <comment>(Specify your ethernet interface)</comment>
242 config_ppp0=( "ppp" )
243 link_ppp0="eth0" <comment>(Specify your ethernet interface)</comment>
244 plugins_ppp0=( "pppoe" )
245 username_ppp0='user'
246 password_ppp0='password'
247 pppd_ppp0=(
248 "noauth"
249 "defaultroute"
250 "usepeerdns"
251 "holdoff 3"
252 "child-timeout 60"
253 "lcp-echo-interval 15"
254 "lcp-echo-failure 3"
255 noaccomp noccp nobsdcomp nodeflate nopcomp novj novjccomp
256 )
257
258 depend_ppp0() {
259 need net.eth0
260 }
261 </pre>
262
263 <p>
264 You can also set your password in <path>/etc/ppp/pap-secrets</path>.
265 </p>
266
267 <pre caption="Sample /etc/ppp/pap-secrets">
268 <comment># The * is important</comment>
269 "username" * "password"
270 </pre>
271
272 <p>
273 If you use PPPoE with a USB modem you'll need to emerge <c>br2684ctl</c>. Please
274 read <path>/usr/portage/net-dialup/speedtouch-usb/files/README</path> for
275 information on how to properly configure it.
276 </p>
277
278 <impo>
279 Please carefully read the section on ADSL and PPP in
280 <path>/etc/conf.d/net.example</path>. It contains many more detailed
281 explanations of all the settings your particular PPP setup will likely need.
282 </impo>
283
284 </body>
285 </section>
286 <section id="apipa">
287 <title>APIPA (Automatic Private IP Addressing)</title>
288 <body>
289
290 <p>
291 APIPA tries to find a free address in the range 169.254.0.0-169.254.255.255 by
292 arping a random address in that range on the interface. If no reply is found
293 then we assign that address to the interface.
294 </p>
295
296 <p>
297 This is only useful for LANs where there is no DHCP server and you don't connect
298 directly to the internet and all other computers use APIPA.
299 </p>
300
301 <p>
302 For APIPA support, emerge <c>net-misc/iputils</c> or <c>net-analyzer/arping</c>.
303 </p>
304
305 <pre caption="APIPA configuration in /etc/conf.d/net">
306 <comment># Try DHCP first - if that fails then fallback to APIPA</comment>
307 config_eth0=( "dhcp" )
308 fallback_eth0=( "apipa" )
309
310 <comment># Just use APIPA</comment>
311 config_eth0=( "apipa" )
312 </pre>
313
314 </body>
315 </section>
316 <section>
317 <title>Bonding</title>
318 <body>
319
320 <p>
321 For link bonding/trunking emerge <c>net-misc/ifenslave</c>.
322 </p>
323
324 <p>
325 Bonding is used to increase network bandwidth. If you have two network cards
326 going to the same network, you can bond them together so your applications see
327 just one interface but they really use both network cards.
328 </p>
329
330 <pre caption="bonding configuration in /etc/conf.d/net">
331 <comment># To bond interfaces together</comment>
332 slaves_bond0="eth0 eth1 eth2"
333
334 <comment># You may not want to assign an IP to the bonded interface</comment>
335 config_bond0=( "null" )
336
337 <comment># Depend on eth0, eth1 and eth2 as they may require extra configuration</comment>
338 depend_bond0() {
339 need net.eth0 net.eth1 net.eth2
340 }
341 </pre>
342
343 </body>
344 </section>
345 <section>
346 <title>Bridging (802.1d support)</title>
347 <body>
348
349 <p>
350 For bridging support emerge <c>net-misc/bridge-utils</c>.
351 </p>
352
353 <p>
354 Bridging is used to join networks together. For example, you may have a server
355 that connects to the internet via an ADSL modem and a wireless access card to
356 enable other computers to connect to the internet via the ADSL modem. You could
357 create a bridge to join the two interfaces together.
358 </p>
359
360 <pre caption="Bridge configuration in /etc/conf.d/net">
361 <comment># Configure the bridge - "man btctl" for more details</comment>
362 brctl_br0=( "setfd 0" "sethello 0" "stp off" )
363
364 <comment># To add ports to bridge br0</comment>
365 bridge_br0="eth0 eth1"
366
367 <comment># You need to configure the ports to null values so dhcp does not get started</comment>
368 config_eth0=( "null" )
369 config_eth1=( "null" )
370
371 <comment># Finally give the bridge an address - you could use DHCP as well</comment>
372 config_br0=( "192.168.0.1/24" )
373
374 <comment># Depend on eth0 and eth1 as they may require extra configuration</comment>
375 depend_br0() {
376 need net.eth0 net.eth1
377 }
378 </pre>
379
380 <impo>
381 For using some bridge setups, you may need to consult the <uri
382 link="?part=4&amp;chap=2#variable_name">variable name</uri> documentation.
383 </impo>
384
385 </body>
386 </section>
387 <section>
388 <title>MAC Address</title>
389 <body>
390
391 <p>
392 You don't need to emerge anything for changing the MAC address of your
393 interface if you have <c>sys-apps/baselayout-1.11.14</c> or newer and want to
394 change to a specific MAC address. However, if you need to change to a random MAC
395 address or have a baselayout older than the version mentioned above, you have
396 to emerge <c>net-analyzer/macchanger</c> to be able to make use of this feature.
397 </p>
398
399 <pre caption="MAC Address change example">
400 <comment># To set the MAC address of the interface</comment>
401 mac_eth0="00:11:22:33:44:55"
402
403 <comment># To randomize the last 3 bytes only</comment>
404 mac_eth0="random-ending"
405
406 <comment># To randomize between the same physical type of connection (e.g. fibre,
407 # copper, wireless) , all vendors</comment>
408 mac_eth0="random-samekind"
409
410 <comment># To randomize between any physical type of connection (e.g. fibre, copper,
411 # wireless) , all vendors</comment>
412 mac_eth0="random-anykind"
413
414 <comment># Full randomization - WARNING: some MAC addresses generated by this may
415 # NOT act as expected</comment>
416 mac_eth0="random-full"
417 </pre>
418
419 </body>
420 </section>
421 <section>
422 <title>Tunnelling</title>
423 <body>
424
425 <p>
426 You don't need to emerge anything for tunnelling as the interface handler can do
427 it for you.
428 </p>
429
430 <pre caption="Tunnelling configuration in /etc/conf.d/net">
431 <comment># For GRE tunnels</comment>
432 iptunnel_vpn0="mode gre remote 207.170.82.1 key 0xffffffff ttl 255"
433
434 <comment># For IPIP tunnels</comment>
435 iptunnel_vpn0="mode ipip remote 207.170.82.2 ttl 255"
436
437 <comment># To configure the interface</comment>
438 config_vpn0=( "192.168.0.2 peer 192.168.1.1" )
439 </pre>
440
441 </body>
442 </section>
443 <section>
444 <title>VLAN (802.1q support)</title>
445 <body>
446
447 <p>
448 For VLAN support, emerge <c>net-misc/vconfig</c>.
449 </p>
450
451 <p>
452 Virtual LAN is a group of network devices that behave as if they were connected
453 to a single network segment - even though they may not be. VLAN members can only
454 see members of the same VLAN even though they may share the same physical
455 network.
456 </p>
457
458 <pre caption="VLAN configuration in /etc/conf.d/net">
459 <comment># Specify the VLAN numbers for the interface like so</comment>
460 <comment># Please ensure your VLAN IDs are NOT zero-padded</comment>
461 vlans_eth0="1 2"
462
463 <comment># You can also configure the VLAN</comment>
464 <comment># see for vconfig man page for more details</comment>
465 vconfig_eth0=( "set_name_type VLAN_PLUS_VID_NO_PAD" )
466 vconfig_vlan1=( "set_flag 1" "set_egress_map 2 6" )
467
468 <comment># Configure the interface as usual</comment>
469 config_vlan1=( "172.16.3.1 netmask 255.255.254.0" )
470 config_vlan2=( "172.16.2.1 netmask 255.255.254.0" )
471 </pre>
472
473 <impo>
474 For using some VLAN setups, you may need to consult the <uri
475 link="?part=4&amp;chap=2#variable_name">variable name</uri> documentation.
476 </impo>
477
478 </body>
479 </section>
480
481 </sections>

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