网卡接口配置——bonding

Bonding就是将多块网卡绑定同一IP地址对外提供服务，可以实现高可用或者负载均衡。当然，直接给两块网卡设置同一IP地址是不可能的。通过bonding，虚拟一块网卡对外提供连接，物理网卡的被修改为相同的MAC地址。

一、Bonding的常用工作模式

Mode 0 (balance-rr)轮转（ Round-robin）策略：从头到尾顺序的在每一个slave接口上面发送数据包。本模式提供负载均衡和容错的能力。 Mode 1 (active-backup)活动-备份（主备）策略：在绑定中，只有一个slave被激活。当且仅当活动的slave接口失败时才会激活其他slave。为了避免交换机发生混乱此时绑定的MAC地址只有一个外部端口上可见。 Mode 3 (broadcast)广播策略：在所有的slave接口上传送所有的报文。本模式提供容错能力。

二、Bonding配置

创建bonding设备的配置文件：

#vim /etc/sysconfig/network-scripts/ifcfg-bond0

DEVICE=bond0

BOOTPROTO=none

BONDING_OPTS=“miimon=100 mode=0”

#vim /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

BOOTPROTO=none

MASTER=bond0

SLAVE=yes

USERCTL=no

说明：miimon是用来进行链路监测的。如果miimon=100，那么系统每100ms 监测一次链路连接状态，如果有一条线路不通就转入另一条线路查看bond0状态：

cat /proc/net/bonding/bond

关于bonding的详细配置请参照：

/usr/src/linux-3.18.41/Documentation/networking/bonding.txt

三、bonding实验演示

步骤1：首先確定自己的操作系统是否支持bonding

[root@CentOS6 ~]# modinfo bonding
filename:       /lib/modules/2.6.32-642.el6.x86_64/kernel/drivers/net/bonding/bonding.ko
author:         Thomas Davis, tadavis@lbl.gov and many others
description:    Ethernet Channel Bonding Driver, v3.7.1
version:        3.7.1
...

如果没有消息返回，說明內核不支持bonding，需要重新编译內核。步骤2：创建bonding配置文件

[root@CentOS network-scripts]# cat ifcfg-bond0
DEVICE=bond0
BOOTPROTO=none
IPADDR=192.168.1.9
GATEWAY=192.168.1.1
PREFIX=24
DNS1=8.8.8.8
BONDING_OPTS="miimon=100 mode=1"

步骤3：修改网卡配置文件

[root@CentOS network-scripts]# cat ifcfg-eth0
DEVICE=eth0
BOOTPROTO=none
MASTER=bond0
SLAVE=yes
[root@CentOS network-scripts]# cat ifcfg-eth1
DEVICE=eth1
BOOTOPRO=none
MASTER=bond0
SLAVE=yes

步骤4：重启网络服务

[root@CentOS network-scripts]# service network restart
Shutting down interface bond0:
...

步骤5：查看配置情况

[root@CentOS network-scripts]# ifconfig
bond0     Link encap:Ethernet  HWaddr 00:0C:29:30:84:C4
inet addr:192.168.1.9  Bcast:192.168.1.255  Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe30:84c4/64 Scope:Link
UP BROADCAST RUNNING MASTER MULTICAST  MTU:1500  Metric:1
RX packets:1000 errors:0 dropped:0 overruns:0 frame:0
TX packets:488 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:82884 (80.9 KiB)  TX bytes:56939 (55.6 KiB)

eth0      Link encap:Ethernet  HWaddr 00:0C:29:30:84:C4
UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
RX packets:1095 errors:0 dropped:0 overruns:0 frame:0
TX packets:677 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:95368 (93.1 KiB)  TX bytes:75001 (73.2 KiB)

eth1      Link encap:Ethernet  HWaddr 00:0C:29:30:84:C4
UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
RX packets:243 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:14734 (14.3 KiB)  TX bytes:614 (614.0 b)
...

[root@CentOS network-scripts]# cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: eth0
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 00:0c:29:30:84:c4
Slave queue ID: 0

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 00:0c:29:30:84:ce
Slave queue ID: 0

步骤6：测试