bonding(绑定)是一种Linux系统下的网卡绑定技术，可以把服务器上n个物理网卡在系统内部抽象(绑定)成一个逻辑上的网卡，能够提升网络吞吐量、实现网络冗余、负载等功能，有很多优势。
bonding技术是Linux系统内核层面实现的，它是一个内核模块(驱动)。使用它需要系统有这个模块, 我们可以modinfo命令查看下这个模块的信息, 一般来说都支持.
# modinfo bonding filename: /lib/modules/2.6.32-642.1.1.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 license: GPL alias: rtnl-link-bond srcversion: F6C1815876DCB3094C27C71 depends: vermagic: 2.6.32-642.1.1.el6.x86_64 SMP mod_unload modversions parm: max_bonds:Max number of bonded devices (int) parm: tx_queues:Max number of transmit queues (default = 16) (int) parm: num_grat_arp:Number of peer notifications to send on failover event (alias of num_unsol_na) (int) parm: num_unsol_na:Number of peer notifications to send on failover event (alias of num_grat_arp) (int) parm: miimon:Link check interval in milliseconds (int) parm: updelay:Delay before considering link up, in milliseconds (int) parm: downdelay:Delay before considering link down, in milliseconds (int) parm: use_carrier:Use netif_carrier_ok (vs MII ioctls) in miimon; 0 for off, 1 for on (default) (int) parm: mode:Mode of operation; 0 for balance-rr, 1 for active-backup, 2 for balance-xor, 3 for broadcast, 4 for 802.3ad, 5 for balance-tlb, 6 for balance-alb (charp) parm: primary:Primary network device to use (charp) parm: primary_reselect:Reselect primary slave once it comes up; 0 for always (default), 1 for only if speed of primary is better, 2 for only on active slave failure (charp) parm: lacp_rate:LACPDU tx rate to request from 802.3ad partner; 0 for slow, 1 for fast (charp) parm: ad_select:803.ad aggregation selection logic; 0 for stable (default), 1 for bandwidth, 2 for count (charp) parm: min_links:Minimum number of available links before turning on carrier (int) parm: xmit_hash_policy:balance-xor and 802.3ad hashing method; 0 for layer 2 (default), 1 for layer 3+4, 2 for layer 2+3 (charp) parm: arp_interval:arp interval in milliseconds (int) parm: arp_ip_target:arp targets in n.n.n.n form (array of charp) parm: arp_validate:validate src/dst of ARP probes; 0 for none (default), 1 for active, 2 for backup, 3 for all (charp) parm: arp_all_targets:fail on any/all arp targets timeout; 0 for any (default), 1 for all (charp) parm: fail_over_mac:For active-backup, do not set all slaves to the same MAC; 0 for none (default), 1 for active, 2 for follow (charp) parm: all_slaves_active:Keep all frames received on an interface by setting active flag for all slaves; 0 for never (default), 1 for always. (int) parm: resend_igmp:Number of IGMP membership reports to send on link failure (int) parm: packets_per_slave:Packets to send per slave in balance-rr mode; 0 for a random slave, 1 packet per slave (default), >1 packets per slave. (int) parm: lp_interval:The number of seconds between instances where the bonding driver sends learning packets to each slaves peer switch. The default is 1. (uint) modinfo bonding
bonding的七种工作模式:
bonding技术提供了七种工作模式，在使用的时候需要指定一种，每种有各自的优缺点.
balance-rr (mode=0) 默认, 有高可用 (容错) 和负载均衡的功能, 需要交换机的配置，每块网卡轮询发包 (流量分发比较均衡).
active-backup (mode=1) 只有高可用 (容错) 功能, 不需要交换机配置, 这种模式只有一块网卡工作, 对外只有一个mac地址。缺点是端口利用率比较低
balance-xor (mode=2) 不常用
broadcast (mode=3) 不常用
802.3ad (mode=4) IEEE 802.3ad 动态链路聚合，需要交换机配置，没用过
balance-tlb (mode=5) 不常用
balance-alb (mode=6) 有高可用 ( 容错 )和负载均衡的功能，不需要交换机配置 (流量分发到每个接口不是特别均衡)