en/handbook/hb-net-modules.xml

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<!DOCTYPE sections SYSTEM "/dtd/book.dtd">

<!-- The content of this document is licensed under the CC-BY-SA license -->
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<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-net-modules.xml,v 1.25 2009/02/13 04:40:27 nightmorph Exp $ -->

<sections>

<abstract>
Gentoo provides you flexible networking - here you are told about choosing
different DHCP clients, setting up bonding, bridging, VLANs and more.
</abstract>

<version>9</version>
<date>2011-08-13</date>

<section>
<title>Network Modules</title>
<body>

<p>
We now support modular networking scripts, which means we can easily add support
for new interface types and configuration modules while keeping compatibility
with existing ones.
</p>

<p>
Modules load by default if the package they need is installed.  If you specify a
module here that doesn't have its package installed then you get an error
stating which package you need to install. Ideally, you only use the modules
setting when you have two or more packages installed that supply the same
service and you need to prefer one over the other.
</p>

<note>
All settings discussed here are stored in <path>/etc/conf.d/net</path> unless 
otherwise specified.
</note>

<pre caption="Module preference">
<comment># Prefer iproute2 over ifconfig</comment>
modules="iproute2"

<comment># You can also specify other modules for an interface
# In this case we prefer pump over dhcpcd</comment>
modules_eth0="pump"

<comment># You can also specify which modules not to use - for example you may be
# using a supplicant or linux-wlan-ng to control wireless configuration but
# you still want to configure network settings per ESSID associated with.</comment>
modules="!iwconfig"
</pre>

</body>
</section>
<section>
<title>Interface Handlers</title>
<body>

<p>
We provide two interface handlers presently: <c>ifconfig</c> and
<c>iproute2</c>. You need one of these to do any kind of network configuration.
</p>

<p>
<c>ifconfig</c> is the current Gentoo default and it's included in the system
profile. <c>iproute2</c> is a more powerful and flexible package, but it's not
included by default.
</p>

<pre caption="To install iproute2">
# <i>emerge sys-apps/iproute2</i>

<comment># To prefer iproute2 over ifconfig if both are installed</comment>
modules="iproute2"
</pre>

<p>
As both <c>ifconfig</c> and <c>iproute2</c> do very similar things we allow
their basic configuration to work with each other. For example both the below
code snippet work regardless of which module you are using.
</p>

<pre caption="ifconfig and iproute2 examples">
config_eth0="192.168.0.2/24"
config_eth0="192.168.0.2 netmask 255.255.255.0"

<comment># We can also specify broadcast</comment>
config_eth0="192.168.0.2/24 brd 192.168.0.255"
config_eth0="192.168.0.2 netmask 255.255.255.0 broadcast 192.168.0.255"
</pre>

</body>
</section>
<section id="dhcp">
<title>DHCP</title>
<body>

<p>
DHCP is a means of obtaining network information (IP address, DNS servers,
Gateway, etc) from a DHCP server. This means that if there is a DHCP server
running on the network, you just have to tell each client to use DHCP and it
sets up the network all by itself. Of course, you will have to configure for
other things like wireless, PPP or other things if required before you can use
DHCP.
</p>

<p>
DHCP can be provided by <c>dhclient</c>, <c>dhcpcd</c>, or <c>pump</c>. Each
DHCP module has its pros and cons - here's a quick run down.
</p>

<table>
<tr>
  <th>DHCP Module</th>
  <th>Package</th>
  <th>Pros</th>
  <th>Cons</th>
</tr>
<tr>
  <ti><c>dhclient</c></ti>
  <ti><c>net-misc/dhcp</c></ti>
  <ti>
    Made by ISC, the same people who make the BIND DNS software. Very 
    configurable
  </ti>
  <ti>
    Configuration is overly complex, software is quite bloated, cannot get 
    NTP servers from DHCP, does not send hostname by default
  </ti>
</tr>
<tr>
  <ti><c>dhcpcd</c></ti>
  <ti><c>net-misc/dhcpcd</c></ti>
  <ti>
    Long time Gentoo default, no reliance on outside tools, actively developed
    by Gentoo
  </ti>
  <ti>Can be slow at times, does not yet daemonize when lease is infinite</ti>
</tr>
<tr>
  <ti><c>pump</c></ti>
  <ti><c>net-misc/pump</c></ti>
  <ti>
    Lightweight, no reliance on outside tools
  </ti>
  <ti>
    No longer maintained upstream, unreliable, especially over modems, cannot
    get NIS servers from DHCP
  </ti>
</tr>
</table>
     
<p>
If you have more than one DHCP client installed, you need to specify which one
to use - otherwise we default to <c>dhcpcd</c> if available.
</p>

<p>
To send specific options to the DHCP module, use <c>module_eth0="..."</c>
<e>(change module to the DHCP module you're using - i.e. <c>dhcpcd_eth0</c>)</e>.
</p>

<p>
We try and make DHCP relatively agnostic - as such we support the following
commands using the <c>dhcp_eth0</c> variable. The default is not to set any of
them:
</p>

<ul>
  <li><c>release</c> - releases the IP address for re-use</li>
  <li><c>nodns</c> - don't overwrite <path>/etc/resolv.conf</path></li>
  <li><c>nontp</c> - don't overwrite <path>/etc/ntp.conf</path></li>
  <li><c>nonis</c> - don't overwrite <path>/etc/yp.conf</path></li>
</ul>

<pre caption="Sample DHCP configuration in /etc/conf.d/net">
<comment># Only needed if you have more than one DHCP module installed</comment>
modules="dhcpcd"

config_eth0="dhcp"
dhcpcd_eth0="-t 10" <comment># Timeout after 10 seconds</comment>
dhcp_eth0="release nodns nontp nonis" <comment># Only get an address</comment>
</pre>

<note>
<c>dhcpcd</c> and <c>pump</c> send the current hostname to the
DHCP server by default so you don't need to specify this anymore.
</note>

</body>
</section>
<section>
<title>ADSL with PPPoE/PPPoA</title>
<body>

<p>
First we need to install the ADSL software.
</p>

<pre caption="Install the ppp package">
# <i>emerge net-dialup/ppp</i>
</pre>

<p>
Second, create the PPP net script and the net script for the ethernet interface
to be used by PPP:
</p>

<pre caption="Creating the PPP and ethernet scripts">
# <i>ln -s /etc/init.d/net.lo /etc/init.d/net.ppp0</i>
# <i>ln -s /etc/init.d/net.lo /etc/init.d/net.eth0</i>
</pre>

<p>
Be sure to set <c>rc_depend_strict</c> to "YES" in <path>/etc/rc.conf</path>.
</p>

<p>
Now we need to configure <path>/etc/conf.d/net</path>.
</p>

<pre caption="A basic PPPoE setup">
config_eth0=null <comment>(Specify your ethernet interface)</comment>
config_ppp0="ppp"
link_ppp0="eth0" <comment>(Specify your ethernet interface)</comment>
plugins_ppp0="pppoe"
username_ppp0='user'
password_ppp0='password'
pppd_ppp0="
noauth
defaultroute
usepeerdns
holdoff 3
child-timeout 60
lcp-echo-interval 15
lcp-echo-failure 3
noaccomp noccp nobsdcomp nodeflate nopcomp novj novjccomp"

rc_need_ppp0="net.eth0"
</pre>

<p>
You can also set your password in <path>/etc/ppp/pap-secrets</path>.
</p>

<pre caption="Sample /etc/ppp/pap-secrets">
<comment># The * is important</comment>
"username"  *  "password"
</pre>

<p>
If you use PPPoE with a USB modem you'll need to emerge <c>br2684ctl</c>. Please
read <path>/usr/portage/net-dialup/speedtouch-usb/files/README</path> for
information on how to properly configure it.
</p>

<impo>
Please carefully read the section on ADSL and PPP in
<path>/usr/share/doc/openrc-0.8.3-r1/net.example.bz2</path>. It contains many
more detailed explanations of all the settings your particular PPP setup will
likely need. Of course, change <c>0.8.3-r1</c> with the version of OpenRC
installed on your system.
</impo>

</body>
</section>
<section id="apipa">
<title>APIPA (Automatic Private IP Addressing)</title>
<body>

<p>
APIPA tries to find a free address in the range 169.254.0.0-169.254.255.255 by
arping a random address in that range on the interface. If no reply is found
then we assign that address to the interface.
</p>

<p>
This is only useful for LANs where there is no DHCP server and you don't connect
directly to the internet and all other computers use APIPA.
</p>

<p>
For APIPA support, emerge <c>net-misc/iputils</c> or <c>net-analyzer/arping</c>.
</p>

<pre caption="APIPA configuration in /etc/conf.d/net">
<comment># Try DHCP first - if that fails then fallback to APIPA</comment>
config_eth0="dhcp"
fallback_eth0="apipa"

<comment># Just use APIPA</comment>
config_eth0="apipa"
</pre>

</body>
</section>
<section>
<title>Bonding</title>
<body>

<p>
For link bonding/trunking emerge <c>net-misc/ifenslave</c>.
</p>

<p>
Bonding is used to increase network bandwidth. If you have two network cards
going to the same network, you can bond them together so your applications see
just one interface but they really use both network cards.
</p>

<pre caption="bonding configuration in /etc/conf.d/net">
<comment># To bond interfaces together</comment>
slaves_bond0="eth0 eth1 eth2"

<comment># You may not want to assign an IP to the bonded interface</comment>
config_bond0="null"

<comment># Depend on eth0, eth1 and eth2 as they may require extra configuration</comment>
rc_need_bond0="net.eth0 net.eth1 net.eth2"
</pre>

</body>
</section>
<section>
<title>Bridging (802.1d support)</title>
<body>

<p>
For bridging support emerge <c>net-misc/bridge-utils</c>.
</p>

<p>
Bridging is used to join networks together. For example, you may have a server
that connects to the internet via an ADSL modem and a wireless access card to
enable other computers to connect to the internet via the ADSL modem. You could
create a bridge to join the two interfaces together.
</p>

<pre caption="Bridge configuration in /etc/conf.d/net">
<comment># Configure the bridge - "man brctl" for more details</comment>
brctl_br0="setfd 0" "sethello 0" "stp off"

<comment># To add ports to bridge br0</comment>
bridge_br0="eth0 eth1"

<comment># You need to configure the ports to null values so dhcp does not get started</comment>
config_eth0="null"
config_eth1="null"

<comment># Finally give the bridge an address - you could use DHCP as well</comment>
config_br0="192.168.0.1/24"

<comment># Depend on eth0 and eth1 as they may require extra configuration</comment>
rc_need_br0="net.eth0 net.eth1"
</pre>

<impo>
For using some bridge setups, you may need to consult the <uri
link="?part=4&amp;chap=2#variable_name">variable name</uri> documentation.
</impo>

</body>
</section>
<section>
<title>MAC Address</title>
<body>

<p>
If you need to, you can change the MAC address of your interfaces through
the network configuration file too.
</p>

<pre caption="MAC Address change example">
<comment># To set the MAC address of the interface</comment>
mac_eth0="00:11:22:33:44:55"

<comment># To randomize the last 3 bytes only</comment>
mac_eth0="random-ending"

<comment># To randomize between the same physical type of connection (e.g. fibre,
# copper, wireless) , all vendors</comment>
mac_eth0="random-samekind"

<comment># To randomize between any physical type of connection (e.g. fibre, copper,
# wireless) , all vendors</comment>
mac_eth0="random-anykind"

<comment># Full randomization - WARNING: some MAC addresses generated by this may
# NOT act as expected</comment>
mac_eth0="random-full"
</pre>

</body>
</section>
<section>
<title>Tunnelling</title>
<body>

<p>
You don't need to emerge anything for tunnelling as the interface handler can do
it for you.
</p>

<pre caption="Tunnelling configuration in /etc/conf.d/net">
<comment># For GRE tunnels</comment>
iptunnel_vpn0="mode gre remote 207.170.82.1 key 0xffffffff ttl 255"

<comment># For IPIP tunnels</comment>
iptunnel_vpn0="mode ipip remote 207.170.82.2 ttl 255"

<comment># To configure the interface</comment>
config_vpn0="192.168.0.2 peer 192.168.1.1"
</pre>

</body>
</section>
<section>
<title>VLAN (802.1q support)</title>
<body>

<p>
For VLAN support, emerge <c>net-misc/vconfig</c>.
</p>

<p>
Virtual LAN is a group of network devices that behave as if they were connected
to a single network segment - even though they may not be. VLAN members can only
see members of the same VLAN even though they may share the same physical
network.
</p>

<pre caption="VLAN configuration in /etc/conf.d/net">
<comment># Specify the VLAN numbers for the interface like so</comment>
<comment># Please ensure your VLAN IDs are NOT zero-padded</comment>
vlans_eth0="1 2"

<comment># You can also configure the VLAN</comment>
<comment># see for vconfig man page for more details</comment>
vconfig_eth0="set_name_type VLAN_PLUS_VID_NO_PAD"
vconfig_vlan1="set_flag 1" "set_egress_map 2 6"

<comment># Configure the interface as usual</comment>
config_vlan1="172.16.3.1 netmask 255.255.254.0"
config_vlan2="172.16.2.1 netmask 255.255.254.0"
</pre>

<impo>
For using some VLAN setups, you may need to consult the <uri
link="?part=4&amp;chap=2#variable_name">variable name</uri> documentation.
</impo>

</body>
</section>

</sections>
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	swift	1.26	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-net-modules.xml,v 1.25 2009/02/13 04:40:27 nightmorph 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	swift	1.26	<version>9</version>
17			<date>2011-08-13</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	swift	1.26	modules="iproute2"
45	swift	1.1
46			<comment># You can also specify other modules for an interface
47	nightmorph	1.25	# In this case we prefer pump over dhcpcd</comment>
48	swift	1.26	modules_eth0="pump"
49	swift	1.1
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	swift	1.26	modules="!iwconfig"
54	swift	1.1	</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	swift	1.26	modules="iproute2"
78	swift	1.1	</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	swift	1.26	config_eth0="192.168.0.2/24"
88			config_eth0="192.168.0.2 netmask 255.255.255.0"
89	swift	1.1
90			<comment># We can also specify broadcast</comment>
91	swift	1.26	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	swift	1.1	</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	nightmorph	1.25	DHCP can be provided by <c>dhclient</c>, <c>dhcpcd</c>, or <c>pump</c>. Each
112			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	swift	1.1	</table>
155
156			<p>
157	jkt	1.9	If you have more than one DHCP client installed, you need to specify which one
158	jkt	1.10	to use - otherwise we default to <c>dhcpcd</c> if available.
159	swift	1.1	</p>
160
161			<p>
162	jkt	1.10	To send specific options to the DHCP module, use <c>module_eth0="..."</c>
163	flammie	1.17	<e>(change module to the DHCP module you're using - i.e. <c>dhcpcd_eth0</c>)</e>.
164	swift	1.1	</p>
165
166			<p>
167			We try and make DHCP relatively agnostic - as such we support the following
168	jkt	1.10	commands using the <c>dhcp_eth0</c> variable. The default is not to set any of
169			them:
170	swift	1.1	</p>
171
172			<ul>
173	jkt	1.10	<li><c>release</c> - releases the IP address for re-use</li>
174			<li><c>nodns</c> - don't overwrite <path>/etc/resolv.conf</path></li>
175			<li><c>nontp</c> - don't overwrite <path>/etc/ntp.conf</path></li>
176			<li><c>nonis</c> - don't overwrite <path>/etc/yp.conf</path></li>
177	swift	1.1	</ul>
178
179			<pre caption="Sample DHCP configuration in /etc/conf.d/net">
180			<comment># Only needed if you have more than one DHCP module installed</comment>
181	swift	1.26	modules="dhcpcd"
182	swift	1.1
183	swift	1.26	config_eth0="dhcp"
184	swift	1.1	dhcpcd_eth0="-t 10" <comment># Timeout after 10 seconds</comment>
185			dhcp_eth0="release nodns nontp nonis" <comment># Only get an address</comment>
186			</pre>
187
188			<note>
189	nightmorph	1.25	<c>dhcpcd</c> and <c>pump</c> send the current hostname to the
190	jkt	1.10	DHCP server by default so you don't need to specify this anymore.
191	swift	1.1	</note>
192
193			</body>
194			</section>
195			<section>
196	nightmorph	1.23	<title>ADSL with PPPoE/PPPoA</title>
197	swift	1.1	<body>
198
199			<p>
200			First we need to install the ADSL software.
201			</p>
202
203	nightmorph	1.22	<pre caption="Install the ppp package">
204			# <i>emerge net-dialup/ppp</i>
205	swift	1.1	</pre>
206
207	nightmorph	1.22	<p>
208	nightmorph	1.23	Second, create the PPP net script and the net script for the ethernet interface
209			to be used by PPP:
210	nightmorph	1.22	</p>
211
212	nightmorph	1.23	<pre caption="Creating the PPP and ethernet scripts">
213	nightmorph	1.22	# <i>ln -s /etc/init.d/net.lo /etc/init.d/net.ppp0</i>
214	nightmorph	1.23	# <i>ln -s /etc/init.d/net.lo /etc/init.d/net.eth0</i>
215	nightmorph	1.22	</pre>
216	swift	1.1
217			<p>
218	swift	1.26	Be sure to set <c>rc_depend_strict</c> to "YES" in <path>/etc/rc.conf</path>.
219	nightmorph	1.23	</p>
220
221			<p>
222	nightmorph	1.22	Now we need to configure <path>/etc/conf.d/net</path>.
223	swift	1.1	</p>
224
225	nightmorph	1.22	<pre caption="A basic PPPoE setup">
226	swift	1.26	config_eth0=null <comment>(Specify your ethernet interface)</comment>
227			config_ppp0="ppp"
228	nightmorph	1.23	link_ppp0="eth0" <comment>(Specify your ethernet interface)</comment>
229	swift	1.26	plugins_ppp0="pppoe"
230	nightmorph	1.22	username_ppp0='user'
231			password_ppp0='password'
232	swift	1.26	pppd_ppp0="
233			noauth
234			defaultroute
235			usepeerdns
236			holdoff 3
237			child-timeout 60
238			lcp-echo-interval 15
239			lcp-echo-failure 3
240			noaccomp noccp nobsdcomp nodeflate nopcomp novj novjccomp"
241
242			rc_need_ppp0="net.eth0"
243	swift	1.1	</pre>
244
245			<p>
246	nightmorph	1.22	You can also set your password in <path>/etc/ppp/pap-secrets</path>.
247	swift	1.1	</p>
248
249	nightmorph	1.22	<pre caption="Sample /etc/ppp/pap-secrets">
250	swift	1.1	<comment># The * is important</comment>
251	swift	1.4	"username" * "password"
252	swift	1.1	</pre>
253
254	nightmorph	1.23	<p>
255			If you use PPPoE with a USB modem you'll need to emerge <c>br2684ctl</c>. Please
256			read <path>/usr/portage/net-dialup/speedtouch-usb/files/README</path> for
257			information on how to properly configure it.
258			</p>
259
260	nightmorph	1.22	<impo>
261			Please carefully read the section on ADSL and PPP in
262	swift	1.26	<path>/usr/share/doc/openrc-0.8.3-r1/net.example.bz2</path>. It contains many
263			more detailed explanations of all the settings your particular PPP setup will
264			likely need. Of course, change <c>0.8.3-r1</c> with the version of OpenRC
265			installed on your system.
266	nightmorph	1.22	</impo>
267
268	swift	1.1	</body>
269			</section>
270			<section id="apipa">
271			<title>APIPA (Automatic Private IP Addressing)</title>
272			<body>
273
274			<p>
275	jkt	1.9	APIPA tries to find a free address in the range 169.254.0.0-169.254.255.255 by
276			arping a random address in that range on the interface. If no reply is found
277			then we assign that address to the interface.
278	swift	1.1	</p>
279
280			<p>
281	jkt	1.9	This is only useful for LANs where there is no DHCP server and you don't connect
282			directly to the internet and all other computers use APIPA.
283	swift	1.1	</p>
284
285			<p>
286	jkt	1.10	For APIPA support, emerge <c>net-misc/iputils</c> or <c>net-analyzer/arping</c>.
287	swift	1.1	</p>
288
289			<pre caption="APIPA configuration in /etc/conf.d/net">
290			<comment># Try DHCP first - if that fails then fallback to APIPA</comment>
291	swift	1.26	config_eth0="dhcp"
292			fallback_eth0="apipa"
293	swift	1.1
294			<comment># Just use APIPA</comment>
295	swift	1.26	config_eth0="apipa"
296	swift	1.1	</pre>
297
298			</body>
299			</section>
300			<section>
301			<title>Bonding</title>
302			<body>
303
304			<p>
305	jkt	1.10	For link bonding/trunking emerge <c>net-misc/ifenslave</c>.
306	swift	1.1	</p>
307
308			<p>
309	jkt	1.9	Bonding is used to increase network bandwidth. If you have two network cards
310			going to the same network, you can bond them together so your applications see
311			just one interface but they really use both network cards.
312	swift	1.1	</p>
313
314			<pre caption="bonding configuration in /etc/conf.d/net">
315	jkt	1.13	<comment># To bond interfaces together</comment>
316	swift	1.1	slaves_bond0="eth0 eth1 eth2"
317
318			<comment># You may not want to assign an IP to the bonded interface</comment>
319	swift	1.26	config_bond0="null"
320	swift	1.1
321			<comment># Depend on eth0, eth1 and eth2 as they may require extra configuration</comment>
322	swift	1.26	rc_need_bond0="net.eth0 net.eth1 net.eth2"
323	swift	1.1	</pre>
324
325			</body>
326			</section>
327			<section>
328			<title>Bridging (802.1d support)</title>
329			<body>
330
331			<p>
332	jkt	1.10	For bridging support emerge <c>net-misc/bridge-utils</c>.
333	swift	1.1	</p>
334
335			<p>
336	jkt	1.9	Bridging is used to join networks together. For example, you may have a server
337			that connects to the internet via an ADSL modem and a wireless access card to
338			enable other computers to connect to the internet via the ADSL modem. You could
339			create a bridge to join the two interfaces together.
340	swift	1.1	</p>
341
342			<pre caption="Bridge configuration in /etc/conf.d/net">
343	nightmorph	1.24	<comment># Configure the bridge - "man brctl" for more details</comment>
344	swift	1.26	brctl_br0="setfd 0" "sethello 0" "stp off"
345	swift	1.1
346			<comment># To add ports to bridge br0</comment>
347			bridge_br0="eth0 eth1"
348
349			<comment># You need to configure the ports to null values so dhcp does not get started</comment>
350	swift	1.26	config_eth0="null"
351			config_eth1="null"
352	swift	1.1
353			<comment># Finally give the bridge an address - you could use DHCP as well</comment>
354	swift	1.26	config_br0="192.168.0.1/24"
355	swift	1.1
356			<comment># Depend on eth0 and eth1 as they may require extra configuration</comment>
357	swift	1.26	rc_need_br0="net.eth0 net.eth1"
358	swift	1.1	</pre>
359
360			<impo>
361	jkt	1.10	For using some bridge setups, you may need to consult the <uri
362			link="?part=4&chap=2#variable_name">variable name</uri> documentation.
363	swift	1.1	</impo>
364
365			</body>
366			</section>
367			<section>
368			<title>MAC Address</title>
369			<body>
370
371			<p>
372	swift	1.26	If you need to, you can change the MAC address of your interfaces through
373			the network configuration file too.
374	swift	1.1	</p>
375
376			<pre caption="MAC Address change example">
377			<comment># To set the MAC address of the interface</comment>
378			mac_eth0="00:11:22:33:44:55"
379
380			<comment># To randomize the last 3 bytes only</comment>
381			mac_eth0="random-ending"
382
383	flammie	1.17	<comment># To randomize between the same physical type of connection (e.g. fibre,
384	swift	1.1	# copper, wireless) , all vendors</comment>
385			mac_eth0="random-samekind"
386
387	flammie	1.17	<comment># To randomize between any physical type of connection (e.g. fibre, copper,
388	swift	1.1	# wireless) , all vendors</comment>
389			mac_eth0="random-anykind"
390
391			<comment># Full randomization - WARNING: some MAC addresses generated by this may
392			# NOT act as expected</comment>
393			mac_eth0="random-full"
394			</pre>
395
396			</body>
397			</section>
398			<section>
399			<title>Tunnelling</title>
400			<body>
401
402			<p>
403	jkt	1.9	You don't need to emerge anything for tunnelling as the interface handler can do
404			it for you.
405	swift	1.1	</p>
406
407			<pre caption="Tunnelling configuration in /etc/conf.d/net">
408			<comment># For GRE tunnels</comment>
409			iptunnel_vpn0="mode gre remote 207.170.82.1 key 0xffffffff ttl 255"
410
411			<comment># For IPIP tunnels</comment>
412			iptunnel_vpn0="mode ipip remote 207.170.82.2 ttl 255"
413
414			<comment># To configure the interface</comment>
415	swift	1.26	config_vpn0="192.168.0.2 peer 192.168.1.1"
416	swift	1.1	</pre>
417
418			</body>
419			</section>
420			<section>
421			<title>VLAN (802.1q support)</title>
422			<body>
423
424			<p>
425	jkt	1.10	For VLAN support, emerge <c>net-misc/vconfig</c>.
426	swift	1.1	</p>
427
428	swift	1.2	<p>
429	jkt	1.9	Virtual LAN is a group of network devices that behave as if they were connected
430			to a single network segment - even though they may not be. VLAN members can only
431			see members of the same VLAN even though they may share the same physical
432			network.
433	swift	1.1	</p>
434
435			<pre caption="VLAN configuration in /etc/conf.d/net">
436			<comment># Specify the VLAN numbers for the interface like so</comment>
437			<comment># Please ensure your VLAN IDs are NOT zero-padded</comment>
438			vlans_eth0="1 2"
439
440			<comment># You can also configure the VLAN</comment>
441			<comment># see for vconfig man page for more details</comment>
442	swift	1.26	vconfig_eth0="set_name_type VLAN_PLUS_VID_NO_PAD"
443			vconfig_vlan1="set_flag 1" "set_egress_map 2 6"
444	swift	1.1
445			<comment># Configure the interface as usual</comment>
446	swift	1.26	config_vlan1="172.16.3.1 netmask 255.255.254.0"
447			config_vlan2="172.16.2.1 netmask 255.255.254.0"
448	swift	1.1	</pre>
449
450			<impo>
451	jkt	1.10	For using some VLAN setups, you may need to consult the <uri
452			link="?part=4&chap=2#variable_name">variable name</uri> documentation.
453	swift	1.1	</impo>
454
455			</body>
456			</section>
457
458			</sections>