/[gentoo]/xml/htdocs/doc/en/handbook/hb-net-modules.xml
Gentoo

Contents of /xml/htdocs/doc/en/handbook/hb-net-modules.xml

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.20 - (hide annotations) (download) (as text)
Wed Jan 3 20:12:08 2007 UTC (7 years, 7 months ago) by nightmorph
Branch: MAIN
Changes since 1.19: +6 -8 lines
File MIME type: application/xml
fixed dhcpcd pros/cons for bug 159610

1 swift 1.1 <?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 swift 1.2 <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
6 swift 1.1
7 nightmorph 1.20 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-net-modules.xml,v 1.19 2006/10/28 09:17:55 neysx Exp $ -->
8 neysx 1.5
9 swift 1.1 <sections>
10    
11 neysx 1.19 <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 nightmorph 1.20 <version>7.1</version>
17     <date>2006-01-04</date>
18 swift 1.1
19     <section>
20     <title>Network Modules</title>
21     <body>
22    
23     <p>
24 jkt 1.9 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 swift 1.1 </p>
28    
29     <p>
30 jkt 1.9 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 swift 1.1 </p>
36    
37 vapier 1.15 <note>
38     All settings discussed here are stored in <path>/etc/conf.d/net</path> unless
39     otherwise specified.
40     </note>
41    
42 swift 1.1 <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 jkt 1.10 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 swift 1.1 </p>
66    
67     <p>
68 jkt 1.10 <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 swift 1.1 </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 jkt 1.10 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 swift 1.1 </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 jkt 1.10 other things like wireless, PPP or other things if required before you can use
107 swift 1.1 DHCP.
108     </p>
109    
110     <p>
111 jkt 1.10 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 swift 1.1 </p>
114    
115     <table>
116 swift 1.2 <tr>
117     <th>DHCP Module</th>
118     <th>Package</th>
119     <th>Pros</th>
120     <th>Cons</th>
121     </tr>
122     <tr>
123 jkt 1.10 <ti><c>dhclient</c></ti>
124     <ti><c>net-misc/dhcp</c></ti>
125 swift 1.2 <ti>
126 swift 1.3 Made by ISC, the same people who make the BIND DNS software. Very
127     configurable
128 swift 1.2 </ti>
129     <ti>
130 swift 1.3 Configuration is overly complex, software is quite bloated, cannot get
131     NTP servers from DHCP, does not send hostname by default
132 swift 1.2 </ti>
133     </tr>
134     <tr>
135 jkt 1.10 <ti><c>dhcpcd</c></ti>
136     <ti><c>net-misc/dhcpcd</c></ti>
137 swift 1.2 <ti>
138 nightmorph 1.20 Long time Gentoo default, no reliance on outside tools, actively developed
139     by Gentoo
140 swift 1.2 </ti>
141 nightmorph 1.20 <ti>Can be slow at times, does not yet daemonize when lease is infinite</ti>
142 swift 1.2 </tr>
143     <tr>
144 jkt 1.10 <ti><c>pump</c></ti>
145     <ti><c>net-misc/pump</c></ti>
146 swift 1.2 <ti>
147 swift 1.3 Lightweight, no reliance on outside tools
148 swift 1.2 </ti>
149     <ti>
150 swift 1.3 No longer maintained upstream, unreliable, especially over modems, cannot
151     get NIS servers from DHCP
152 swift 1.2 </ti>
153     </tr>
154     <tr>
155 jkt 1.10 <ti><c>udhcpc</c></ti>
156     <ti><c>net-misc/udhcp</c></ti>
157 swift 1.2 <ti>
158 jkt 1.10 Lightweight - smallest DHCP client around, made for embedded systems
159 swift 1.2 </ti>
160     <ti>
161 swift 1.3 Unproven - no distro uses it by default, cannot define a timeout beyond 3
162     seconds
163 swift 1.2 </ti>
164     </tr>
165 swift 1.1 </table>
166    
167     <p>
168 jkt 1.9 If you have more than one DHCP client installed, you need to specify which one
169 jkt 1.10 to use - otherwise we default to <c>dhcpcd</c> if available.
170 swift 1.1 </p>
171    
172     <p>
173 jkt 1.10 To send specific options to the DHCP module, use <c>module_eth0="..."</c>
174 flammie 1.17 <e>(change module to the DHCP module you're using - i.e. <c>dhcpcd_eth0</c>)</e>.
175 swift 1.1 </p>
176    
177     <p>
178     We try and make DHCP relatively agnostic - as such we support the following
179 jkt 1.10 commands using the <c>dhcp_eth0</c> variable. The default is not to set any of
180     them:
181 swift 1.1 </p>
182    
183     <ul>
184 jkt 1.10 <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 swift 1.1 </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 jkt 1.10 <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 swift 1.1 </note>
203    
204     </body>
205     </section>
206     <section>
207     <title>ADSL Modem</title>
208     <body>
209    
210     <p>
211     First we need to install the ADSL software.
212     </p>
213    
214     <pre caption="Install the rp-pppoe package">
215     # <i>emerge net-dialup/rp-pppoe</i>
216     </pre>
217    
218     <warn>
219 jkt 1.10 <c>baselayout-1.11.x</c> supports PPPoE only. Hopefully future versions will
220     support PPPoA.
221 swift 1.1 </warn>
222    
223     <p>
224 vapier 1.14 Now we need to configure <c>eth0</c> to be an ADSL interface and enter our
225     username by updating <path>/etc/conf.d/net</path>.
226 swift 1.1 </p>
227    
228 vapier 1.14 <pre caption="Configure eth0 for ADSL in /etc/conf.d/net">
229 swift 1.1 config_eth0=( "adsl" )
230 jkt 1.8 adsl_user_eth0="username"
231 swift 1.1 </pre>
232    
233     <p>
234     Finally you need to define your username and password in
235 jkt 1.10 <path>/etc/ppp/pap-secrets</path>.
236 swift 1.1 </p>
237    
238     <pre caption="sample /etc/ppp/pap-secrets">
239     <comment># The * is important</comment>
240 swift 1.4 "username" * "password"
241 swift 1.1 </pre>
242    
243     </body>
244     </section>
245     <section id="apipa">
246     <title>APIPA (Automatic Private IP Addressing)</title>
247     <body>
248    
249     <p>
250 jkt 1.9 APIPA tries to find a free address in the range 169.254.0.0-169.254.255.255 by
251     arping a random address in that range on the interface. If no reply is found
252     then we assign that address to the interface.
253 swift 1.1 </p>
254    
255     <p>
256 jkt 1.9 This is only useful for LANs where there is no DHCP server and you don't connect
257     directly to the internet and all other computers use APIPA.
258 swift 1.1 </p>
259    
260     <p>
261 jkt 1.10 For APIPA support, emerge <c>net-misc/iputils</c> or <c>net-analyzer/arping</c>.
262 swift 1.1 </p>
263    
264     <pre caption="APIPA configuration in /etc/conf.d/net">
265     <comment># Try DHCP first - if that fails then fallback to APIPA</comment>
266     config_eth0=( "dhcp" )
267     fallback_eth0=( "apipa" )
268    
269     <comment># Just use APIPA</comment>
270     config_eth0=( "apipa" )
271     </pre>
272    
273     </body>
274     </section>
275     <section>
276     <title>Bonding</title>
277     <body>
278    
279     <p>
280 jkt 1.10 For link bonding/trunking emerge <c>net-misc/ifenslave</c>.
281 swift 1.1 </p>
282    
283     <p>
284 jkt 1.9 Bonding is used to increase network bandwidth. If you have two network cards
285     going to the same network, you can bond them together so your applications see
286     just one interface but they really use both network cards.
287 swift 1.1 </p>
288    
289     <pre caption="bonding configuration in /etc/conf.d/net">
290 jkt 1.13 <comment># To bond interfaces together</comment>
291 swift 1.1 slaves_bond0="eth0 eth1 eth2"
292    
293     <comment># You may not want to assign an IP to the bonded interface</comment>
294     config_bond0=( "null" )
295    
296     <comment># Depend on eth0, eth1 and eth2 as they may require extra configuration</comment>
297     depend_bond0() {
298 swift 1.4 need net.eth0 net.eth1 net.eth2
299 swift 1.1 }
300     </pre>
301    
302     </body>
303     </section>
304     <section>
305     <title>Bridging (802.1d support)</title>
306     <body>
307    
308     <p>
309 jkt 1.10 For bridging support emerge <c>net-misc/bridge-utils</c>.
310 swift 1.1 </p>
311    
312     <p>
313 jkt 1.9 Bridging is used to join networks together. For example, you may have a server
314     that connects to the internet via an ADSL modem and a wireless access card to
315     enable other computers to connect to the internet via the ADSL modem. You could
316     create a bridge to join the two interfaces together.
317 swift 1.1 </p>
318    
319     <pre caption="Bridge configuration in /etc/conf.d/net">
320     <comment># Configure the bridge - "man btctl" for more details</comment>
321     brctl_br0=( "setfd 0" "sethello 0" "stp off" )
322    
323     <comment># To add ports to bridge br0</comment>
324     bridge_br0="eth0 eth1"
325    
326     <comment># You need to configure the ports to null values so dhcp does not get started</comment>
327     config_eth0=( "null" )
328     config_eth1=( "null" )
329    
330     <comment># Finally give the bridge an address - you could use DHCP as well</comment>
331     config_br0=( "192.168.0.1/24" )
332    
333     <comment># Depend on eth0 and eth1 as they may require extra configuration</comment>
334     depend_br0() {
335 swift 1.4 need net.eth0 net.eth1
336 swift 1.1 }
337     </pre>
338    
339     <impo>
340 jkt 1.10 For using some bridge setups, you may need to consult the <uri
341     link="?part=4&amp;chap=2#variable_name">variable name</uri> documentation.
342 swift 1.1 </impo>
343    
344     </body>
345     </section>
346     <section>
347     <title>MAC Address</title>
348     <body>
349    
350     <p>
351 rane 1.11 You don't need to emerge anything for changing the MAC address of your
352     interface if you have <c>sys-apps/baselayout-1.11.14</c> or newer and want to
353 fox2mike 1.12 change to a specific MAC address. However, if you need to change to a random MAC
354     address or have a baselayout older than the version mentioned above, you have
355     to emerge <c>net-analyzer/macchanger</c> to be able to make use of this feature.
356 swift 1.1 </p>
357    
358     <pre caption="MAC Address change example">
359     <comment># To set the MAC address of the interface</comment>
360     mac_eth0="00:11:22:33:44:55"
361    
362     <comment># To randomize the last 3 bytes only</comment>
363     mac_eth0="random-ending"
364    
365 flammie 1.17 <comment># To randomize between the same physical type of connection (e.g. fibre,
366 swift 1.1 # copper, wireless) , all vendors</comment>
367     mac_eth0="random-samekind"
368    
369 flammie 1.17 <comment># To randomize between any physical type of connection (e.g. fibre, copper,
370 swift 1.1 # wireless) , all vendors</comment>
371     mac_eth0="random-anykind"
372    
373     <comment># Full randomization - WARNING: some MAC addresses generated by this may
374     # NOT act as expected</comment>
375     mac_eth0="random-full"
376     </pre>
377    
378     </body>
379     </section>
380     <section>
381     <title>Tunnelling</title>
382     <body>
383    
384     <p>
385 jkt 1.9 You don't need to emerge anything for tunnelling as the interface handler can do
386     it for you.
387 swift 1.1 </p>
388    
389     <pre caption="Tunnelling configuration in /etc/conf.d/net">
390     <comment># For GRE tunnels</comment>
391     iptunnel_vpn0="mode gre remote 207.170.82.1 key 0xffffffff ttl 255"
392    
393     <comment># For IPIP tunnels</comment>
394     iptunnel_vpn0="mode ipip remote 207.170.82.2 ttl 255"
395    
396     <comment># To configure the interface</comment>
397     config_vpn0=( "192.168.0.2 peer 192.168.1.1" )
398     </pre>
399    
400     </body>
401     </section>
402     <section>
403     <title>VLAN (802.1q support)</title>
404     <body>
405    
406     <p>
407 jkt 1.10 For VLAN support, emerge <c>net-misc/vconfig</c>.
408 swift 1.1 </p>
409    
410 swift 1.2 <p>
411 jkt 1.9 Virtual LAN is a group of network devices that behave as if they were connected
412     to a single network segment - even though they may not be. VLAN members can only
413     see members of the same VLAN even though they may share the same physical
414     network.
415 swift 1.1 </p>
416    
417     <pre caption="VLAN configuration in /etc/conf.d/net">
418     <comment># Specify the VLAN numbers for the interface like so</comment>
419     <comment># Please ensure your VLAN IDs are NOT zero-padded</comment>
420     vlans_eth0="1 2"
421    
422     <comment># You can also configure the VLAN</comment>
423     <comment># see for vconfig man page for more details</comment>
424     vconfig_eth0=( "set_name_type VLAN_PLUS_VID_NO_PAD" )
425     vconfig_vlan1=( "set_flag 1" "set_egress_map 2 6" )
426    
427     <comment># Configure the interface as usual</comment>
428     config_vlan1=( "172.16.3.1 netmask 255.255.254.0" )
429     config_vlan2=( "172.16.2.1 netmask 255.255.254.0" )
430     </pre>
431    
432     <impo>
433 jkt 1.10 For using some VLAN setups, you may need to consult the <uri
434     link="?part=4&amp;chap=2#variable_name">variable name</uri> documentation.
435 swift 1.1 </impo>
436    
437     </body>
438     </section>
439    
440     </sections>

  ViewVC Help
Powered by ViewVC 1.1.20