Network configuration /etc/config/network

相关链接: IPv4 配置, IPv6 配置, 静态路由, WAN 接口协议, 编写网络 (Network) 脚本, 编写 DHCP 客户端脚本

一个典型的，使用 OpenWrt 的家用路由器的默认网络栈结构大致如下：

不同的实际设备由于特性及编号规则的差异，可能与上面表格中的内容稍有不同。一个最简单的路由器网络配置通常包含至少两个接口 (lan 和 wan) 及相应的关联设备 (associated devices. br-lan 和 eth0) ，如果可用，还可能会有 switch 部分 。

注：WAN 和 LAN 标签在不同的语境下可能会有不同的涵义。

OpenWrt 使用 UCI 网络子系统（UCI network subsystem）进行中心化的配置管理，配置都保存在文件 /etc/config/network 中。 该 UCI 子系统负责定义不同的交换机 VLAN、接口配置和网络路由。 在完成配置后，需要重新加载 (reload) 或重启 (restart) network 服务，新的配置才会生效。

network 服务使用 netifid 和 wifi 来分别对有线和无线网络进行管理。

用户可以通过 ifup 接口名 和 ifdown 接口名 来手动控制各个接口的开关。“接口名” 对应的是 config interface 部分中的逻辑接口名 (logical interface name) 。 提示：通常重启一个接口只需要执行 ifup 就可以了，因为 ifup 中已经包含了 ifdown 的操作。

需要注意的是，无线接口是由外部管理的 (managed externally)，ifup 可能会打破这些接口和网桥的关联关系。 因此对无线接口的管理需要在运行 ifup 后再运行一次 wifi up，以重新建立与网桥的连接。

# 网络服务软重新加载
service network reload
 
# 网络服务硬重启
service network restart
 
# 重新连接接口
ifdown wan6
ifup wan6
 
# 重新加载无线接口
wifi down
wifi up
 
# 列出接口列表
ubus list network.interface.*
 
# 状态信息
ifstatus wan6

下面是 TL-WR1043ND 路由器的网络 UCI 子系统配置

config interface 'loopback'
	option device 'lo'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'
 
config globals 'globals'
	option ula_prefix 'fd27:70fa:5c1d::/48'
 
config device 'lan_br'
	option name 'br-lan'
	option type 'bridge'
	list ports 'eth0.1'
 
config interface 'lan'
	option device 'br-lan'
	option proto 'static'
	option netmask '255.255.255.0'
	option ip6assign '60'
	option ipaddr '192.168.1.1'
 
config interface 'wan'
	option device 'eth0.2'
	option proto 'dhcp'
 
config interface 'wan6'
	option device 'eth0.2'
	option proto 'dhcpv6'
 
config switch
	option name 'switch0'
	option reset '1'
	option enable_vlan '1'
 
config switch_vlan
	option device 'switch0'
	option vlan '1'
	option ports '1 2 3 4 5t'
 
config switch_vlan
	option device 'switch0'
	option vlan '2'
	option ports '0 5t'

该部分包含接口无关（interface-independent）的、控制通用网络配置的选项。

config globals 'globals'
	option ula_prefix 'fd27:70fa:5c1d::/48'

当 L2 和 L3 设备是同一个设备时 （即 MAC 和 IP 地址指同一个物理接口时），device 部分可以省略

config device 'lan_br'
	option name 'br-lan'
	option type 'bridge'
	list ports 'eth0.1'

在 eth2 接口上启用流控制（flow control） 的例子

config device                          
        option name 'eth2'                        
        option rxpause '1'             
        option txpause '1'

TODO: 将所有网桥、Layer 2 相关内容加到这里

interface 部分声明 (declare) 了一个逻辑网络所包含的 IP 地址设置、别名、路由、物理接口名称及防火墙规则 等属性 - 这些属性在 OpenWrt 配置中扮演着核心角色。

最简单的接口声明只需要下面几行配置：

config 'interface' 'wan'
	option 'proto' 'dhcp'
	option 'device' 'eth0.2'

• wan: 一个逻辑接口名（logical interface name），该名称不能重复；
• dhcp: 指定接口协议（itnerface protocol），此处以 DHCP 为例；
• eth0.2: 与该部分相关联的物理接口（physical interface）。（译注：原文说的是物理接口，但实际上也可以是网桥）

interface protocol 的可选项包括:

根据所用的接口协议的不同，interface 部分可能还会需要补充一些其他的选项。 下一节中会给出每个协议所对应的选项。 若一个协议对应的选项的 “必需” 列中标记为 “是” ，则必须在接口声明中定义该选项，否则可以忽略。

若接口部分没有定义协议（指连 none 都没写），则其他的所有设置都会被完全忽略。这也意味着如果该接口涉及到某个物理网络接口（如 eth0），也会导致该物理接口即使在插了网线的情况下也是 down 状态。（如果填了 “none” 则接口会是 up 的）。

通用选项对所有的协议类型都有效。

名称	类型	是否必需	默认值	描述
device	string	yes(*)	(none)	L3 device name, such as eth0.1, eth2, tun0, br-lan, etc. Needs to match the name option of the respective device section. Do not specify wireless interfaces as their names and behavior can be dynamic and unpredictable, instead assign wireless interfaces to bridges using the network option in wireless configuration. This option may be empty or missing if only a wireless interface references this network or if the protocol is pptp, pppoa, 6in4, etc.
mtu	number	no	(none)	Override the default MTU on this interface
auto	boolean	no	0 for proto none, else 1	Specifies whether to bring up interface on boot
ipv6	boolean	no	1	Specifies whether to enable (1) or disable (0) IPv6 on this interface (Barrier Breaker and later only)
force_link	boolean	no	1 for protocol static, else 0	Specifies whether ip address, route, and optionally gateway are assigned to the interface regardless of the link being active ('1') or only after the link has become active ('0'); when set to '1', carrier sense events do not invoke hotplug handlers
disabled	boolean	no	0	enable or disable the interface section
ip4table	string	no	(none)	IPv4 routing table for routes of this interface, see: ip rule show; ip route show table <ip4table>
ip6table	string	no	(none)	IPv6 routing table for routes of this interface, see: ip -6 rule show; ip -6 route show table <ip6table>

All bridge settings are optional.

Name	Type	Default	Range	Description
bridge_empty	boolean	0	0, 1	Enables creating empty bridges
vlan_filtering	boolean	0	0, 1	Enables VLAN aware bridge mode
igmp_snooping	boolean	0	0, 1	Enables IGMP snooping on the bridge, an optimization that only sends multicast traffic to ports with multicast clients or routers
multicast_querier	boolean	(igmp_snooping setting)	0, 1	IGMP Enables the bridge as a multicast querier, which keeps the multicast group to port mappings current. Only one querier is elected per subnet
query_interval	number	12500	-	IGMP Interval in 1/100 seconds between querier general queries (so default is 125 seconds)
query_response_interval	number	1000	(less than query_interval)	IGMP Max time in 1/100 seconds responses to queries should be sent (increase to make IGMP less bursty)
last_member_interval	number	100	-	IGMP Max time in 1/100s responses to queries after “leave group” messages (the leave latency)
hash_max	number	512	-	IGMP Size of kernel multicast hash table (larger to avoid collisions that disable snooping)
robustness	number	2	-	IGMP Sets Startup Query Count and Last Member Count. Also combined with query_interval and query_response_interval to calculate Group Membership Interval and “other querier” timeout (both other values must be set)
stp	boolean	0	0, 1	Enables the Spanning Tree Protocol (STP) which prevents network loops (and resulting packet storms)
forward_delay	number	2	2 - 30	STP Delay in seconds between port state transitions from Listening → Learning → Forwarding (i.e. bridge ports will be blocked for 2x this value when brought up) NOTE The default 2 is below the minimum 802.1D standard of 4, and STP will be ignored by conforming switches. Set to at least 4 to work with non-OpenWrt switches!
hello_time	number	2	1 - 10	STP Seconds between STP packets
priority	number	32767	0 - 65535	STP Bridge Priority. Lowest priority bridge becomes the Root of the Spanning Tree; most switches default to 32768
ageing_time	number	300	10 - 1000000	STP Expire in seconds for dynamic MAC entries in the Filtering DB
max_age	number	20	6 - 40	STP After current Root Bridge absent this many seconds, attempt to become the Root Bridge (effects the speed a dead bridge is identified)

, see: DSA networking

For many users, the default switch configuration is sufficient. Should the user need to configure the switch differently, LuCI, UCI, or direct editing of /etc/config/network may be used to achieve different configurations. Prior to any reconfiguration of the switch, an understanding of the default configuration is important. As an example, some devices have a single switch-connected interface, and other have two or more.

See also:

• swconfig
• VLAN
• Switch Documentation (Older content, but does give discuss single-interface configuration)

The identifier for the switch(es) may be obtained using:

# swconfig list
Found: switch0 - ag71xx-mdio.0

With the identifier known, the configuration can be viewed:

# swconfig dev switch0 show
Global attributes:
	enable_vlan: 1
	enable_mirror_rx: 0
	enable_mirror_tx: 0
	mirror_monitor_port: 0
	mirror_source_port: 0
	arl_age_time: 300
	arl_table: address resolution table
[...]

There are three types of switch-related configuration stanzas, switch, switch_vlan, and switch_port.

Not all options are available on all hardware. Some limitations may be found with swconfig dev <dev> help. After making changes, check the output of swconfig to determine if the configuration was accepted by the switch hardware.

: The list of options may be incomplete. The details of each option need additional discovery and documentation, including checking of the underlying code. The source of restrictions on value ranges has yet to be identified. Valid values should be confirmed in the code.