1. 简要
双网卡绑定技术在centos7中使用了teaming技术，而在rhel6/centos7中使用的是bonding技术，
在centos7中双网卡绑定既能使用teaming也可以使用bonding，这里推荐使用teaming技术，方便与查看和监控。
2. 原理
这里介绍两种最常见的双网卡绑定模式：
（1） roundrobin - 轮询模式
所有链路处于负载均衡状态，这种模式的特点增加了带宽，同时支持容错能力。
（2） activebackup - 主备模式
一个网卡处于活动状态，另一个处于备份状态，所有流量都在主链路上处理，当活动网卡down掉时，启用备份网卡。
3. 基础环境
系统：centos7
在centos7中，关闭虚拟机添加网卡，再开启虚拟机，系统是不会自动生成网卡的配置文件：
在centos7中要生成网卡配置文件的方法很简单，使用如下命令：
# 查看物理网卡信息 [root@localhost ~]# nmcli dev DEVICE TYPE STATE CONNECTION eno16777736 ethernet connected eno16777736 eno33554984 ethernet connected Wired connection 1 eno50332208 ethernet connected Wired connection 2 lo loopback unmanaged --
上面的信息可以看到，一共有四张网卡，其中lo是本地回环网卡，另外三张为物理网卡。
# 查看网卡连接信息 [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE Wired connection 2 9a1314bf-d273-406a-930a-dc4160dee4ec 802-3-ethernet eno50332208 Wired connection 1 47eef4a3-7fa4-4a73-83ef-1485bda9b950 802-3-ethernet eno33554984 eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736
上面的信息可以查看到一共有3个连接，其中两个有线连接，表示没有设置过的网卡连接，还有一个enoxx连接。接下来要修改两个有线连接的命名方法，并生成网卡配置文件：
# 首先，删除两个无用的有线连接 [root@localhost ~]# nmcli con del 9a1314bf-d273-406a-930a-dc4160dee4ec Connection 'Wired connection 2' (9a1314bf-d273-406a-930a-dc4160dee4ec) successfully deleted. [root@localhost ~]# nmcli con del 47eef4a3-7fa4-4a73-83ef-1485bda9b950 Connection 'Wired connection 1' (47eef4a3-7fa4-4a73-83ef-1485bda9b950) successfully deleted.
# 再次创建新的连接并生成配置文件 [root@localhost ~]# nmcli conn add type ethernet con-name eno50332208 ifname eno50332208 Connection 'eno50332208' (eea2a115-63f8-4f33-be84-12559f02542c) successfully added. [root@localhost ~]# nmcli conn add type ethernet con-name eno33554984 ifname eno33554984 Connection 'eno33554984' (32d2389e-4e82-4419-9d18-5aff8f0be003) successfully added.
# 最后，查看下 [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 eno33554984 32d2389e-4e82-4419-9d18-5aff8f0be003 802-3-ethernet eno33554984 eno50332208 eea2a115-63f8-4f33-be84-12559f02542c 802-3-ethernet eno50332208 [root@localhost ~]# ll /etc/sysconfig/network-scripts/ifcfg-eno* -rw-r--r--. 1 root root 394 Nov 26 05:59 /etc/sysconfig/network-scripts/ifcfg-eno16777736 -rw-r--r--. 1 root root 288 Dec 26 08:44 /etc/sysconfig/network-scripts/ifcfg-eno33554984 -rw-r--r--. 1 root root 288 Dec 26 08:44 /etc/sysconfig/network-scripts/ifcfg-eno50332208
网络连接和配置文件都成功生成了。 接下来通过eno33554984 和 eno50332208 使用teaming模式进行双网卡绑定
4. roundrobin模式：
roundrobin模式也称为轮询模式，它 基于每一个包 ，当某一台服务器的两张网卡设置为roundrobin模式teaming，此时服务器发出的数据包，就会在两个物理
网卡上进行轮询，即第一个数据包走一张网卡，第二个数据包走第二张网卡，依次轮询。
注意：
（1）roundrobin具有容错性，当一张网卡down掉，数据包依然发送成功。
（2）在使用roundrobin模式必须要在交换机上做以太通道，不然会出现网络无法连通。
实际操作：
# 使用nmcli命令操作，创建team接口team0，同时设置teaming模式为roundrobin [root@localhost ~]# nmcli con add type team con-name team0 ifname team0 config '{"runner":{"name": "roundrobin"}}' Connection 'team0' (9dc48bd6-54b9-48db-b7dd-ecf34ae9196f) successfully added.
# 给接口team0设置ip地址 [root@localhost ~]# nmcli con modify team0 ipv4.address '10.0.0.2/24' ipv4.gateway '10.0.0.1' # 设置为手动模式，取消DHCP [root@localhost ~]# nmcli con modify team0 ipv4.method manual
# 将两张物理网卡加入到team中 [root@localhost ~]# nmcli con add type team-slave con-name team0-port1 ifname eno33554984 master team0 Connection 'team0-port1' (22d3640e-f5c8-499c-b0dd-913c8970d800) successfully added. [root@localhost ~]# nmcli con add type team-slave con-name team0-port2 ifname eno50332208 master team0 Connection 'team0-port2' (12660d2a-0e1f-41e6-96b2-53de4fc6b78c) successfully added. [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE team0-port2 12660d2a-0e1f-41e6-96b2-53de4fc6b78c 802-3-ethernet -- eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 team0-port1 22d3640e-f5c8-499c-b0dd-913c8970d800 802-3-ethernet -- team0 9dc48bd6-54b9-48db-b7dd-ecf34ae9196f team team0 eno33554984 32d2389e-4e82-4419-9d18-5aff8f0be003 802-3-ethernet eno33554984 eno50332208 eea2a115-63f8-4f33-be84-12559f02542c 802-3-ethernet eno50332208
# 查看team0的状态 [root@localhost ~]# teamdctl team0 st setup: runner: roundrobin
4.1 roundrobin问题排查
第一次查看出现的是这样的结果，检查下配置：
# 通过直接查看网卡发现team0并没有启动 [root@localhost ~]# ip a | grep team0 5: team0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN # 使用ifup 启动team0并没有成功，继续排查 [root@localhost ~]# ifup team0 [root@localhost ~]# ip a | grep team0 5: team0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
直接sysetmctl restart network 也没有成功。
# 发现team0-port1 team0-port2没有添加成功物理网卡，怎么回事呢？ [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE team0-port2 ec96c1e1-d268-4ba1-a2f9-0133a9f02655 802-3-ethernet -- eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 team0-port1 22d3640e-f5c8-499c-b0dd-913c8970d800 802-3-ethernet -- team0 9dc48bd6-54b9-48db-b7dd-ecf34ae9196f team team0 eno33554984 32d2389e-4e82-4419-9d18-5aff8f0be003 802-3-ethernet eno33554984 eno50332208 eea2a115-63f8-4f33-be84-12559f02542c 802-3-ethernet eno50332208
# 删除掉 [root@localhost ~]# nmcli con del team0-port1 Connection 'team0-port1' (22d3640e-f5c8-499c-b0dd-913c8970d800) successfully deleted. [root@localhost ~]# nmcli con del team0-port2 Connection 'team0-port2' (ec96c1e1-d268-4ba1-a2f9-0133a9f02655) successfully deleted. # 删除两张物理网卡的连接 [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 team0 9dc48bd6-54b9-48db-b7dd-ecf34ae9196f team team0 eno33554984 32d2389e-4e82-4419-9d18-5aff8f0be003 802-3-ethernet eno33554984 eno50332208 eea2a115-63f8-4f33-be84-12559f02542c 802-3-ethernet eno50332208 [root@localhost ~]# nmcli con del eno33554984 eno50332208 Connection 'eno33554984' (32d2389e-4e82-4419-9d18-5aff8f0be003) successfully deleted. Connection 'eno50332208' (eea2a115-63f8-4f33-be84-12559f02542c) successfully deleted. # 删除成功 [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 team0 9dc48bd6-54b9-48db-b7dd-ecf34ae9196f team team0
# 再次将两张物理网卡添加到team [root@localhost ~]# nmcli con add type team-slave con-name team0-port1 ifname eno33554984 master team0 Connection 'team0-port1' (0331ea43-95c0-4106-b388-8484d4c3940d) successfully added. [root@localhost ~]# nmcli con add type team-slave con-name team0-port2 ifname eno50332208 master team0 Connection 'team0-port2' (880f2146-fe93-42dd-8d28-7d0dd50b4011) successfully added. [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE team0-port1 0331ea43-95c0-4106-b388-8484d4c3940d 802-3-ethernet eno33554984 eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 team0 9dc48bd6-54b9-48db-b7dd-ecf34ae9196f team team0 team0-port2 880f2146-fe93-42dd-8d28-7d0dd50b4011 802-3-ethernet eno50332208
现在成功将两张物理网卡绑定到了team组中
# 现在查看team0的状态就出现了，模式是：roundrobin [root@localhost ~]# teamdctl team0 st setup: runner: roundrobin ports: eno33554984 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0 eno50332208 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0
这样，team模式的roundrobin搭建成功。
总结：
在做链路聚合的时候，所要使用到的物理网卡不能独立存在连接，也就是在nmcli con sh查看时，不能独立存在，否则就无法绑定到team模式中。
4.2 测试
因为这里是虚拟机环境，只能通过down掉网卡进行查看。
[root@localhost ~]# teamdctl team0 st setup: runner: roundrobin ports: eno33554984 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0 eno50332208 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0
两张网卡同时在线，现在down掉其中一张网卡，
[root@localhost ~]# nmcli con del team0-port1 Connection 'team0-port1' (0331ea43-95c0-4106-b388-8484d4c3940d) successfully deleted. [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 team0 9dc48bd6-54b9-48db-b7dd-ecf34ae9196f team team0 team0-port2 880f2146-fe93-42dd-8d28-7d0dd50b4011 802-3-ethernet eno50332208 [root@localhost ~]# teamdctl team0 st setup: runner: roundrobin ports: eno50332208 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0
这样就发现eno33554984网卡已经down掉了。
[root@localhost ~]# nmcli con add type team-slave con-name team0-port1 ifname eno33554984 master team0 Connection 'team0-port1' (59acd6bf-affc-4994-a050-83c45816859a) successfully added. [root@localhost ~]# [root@localhost ~]# teamdctl team0 st setup: runner: roundrobin ports: eno33554984 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0 eno50332208 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0
虚拟机环境就这样测试了吧，至于生产环境就直接拔网线，ping测试。
资料有说linux下roundrobin具有容错的效果，为了测试是否有容错的效果，虚拟机做了下更改来验证：
这一次网卡全部改成桥接模式，为了更好的测试是否具有容错性。
roundrobin已经配置完毕。接下来我们down掉一张网卡检查是否具有容错性。
通过虚拟机测试，容错性是存在的。
5. 双网卡绑定activebackup的实现
[root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE team0-port2 2a1aa534-e021-4452-bb0a-2002dabcbc08 802-3-ethernet eno50332208 team0-port1 9a10c9ef-ee9c-4151-9a47-59b4668e8934 802-3-ethernet -- eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 team0 c2278f3f-5c6b-4e1d-b925-514d3c3832b6 team team0 [root@localhost ~]# nmcli con del team0 team0-port1 team0-port2 Connection 'team0' (c2278f3f-5c6b-4e1d-b925-514d3c3832b6) successfully deleted. Connection 'team0-port1' (9a10c9ef-ee9c-4151-9a47-59b4668e8934) successfully deleted. Connection 'team0-port2' (2a1aa534-e021-4452-bb0a-2002dabcbc08) successfully deleted. [root@localhost ~]# nmcli con sh NAME UUID TYPE DEVICE eno16777736 51d00668-2cf5-41da-ad8d-5019d62e98ad 802-3-ethernet eno16777736 # 以上操作就删除了roundrobin模式，恢复到初始状态。
# 添加逻辑网卡team0，并启用activebackup模式 [root@localhost ~]# nmcli con add type team con-name team0 ifname team0 config '{"runner":{"name":"activebackup"}}' Connection 'team0' (f0794e59-419d-4c2a-96b9-464610b6321a) successfully added. # 绑定ip [root@localhost ~]# nmcli con modify team0 ipv4.address 192.168.118.122/24 ipv4.gateway 192.168.118.1 [root@localhost ~]# nmcli con modify team0 ipv4.method manual # 添加物理网卡到activebackup模式 [root@localhost ~]# nmcli con add type team-slave con-name team0-port1 ifname eno33554984 master team0 Connection 'team0-port1' (52656904-6e85-4a04-98b4-2b19773fa290) successfully added. [root@localhost ~]# nmcli con add type team-slave con-name team0-port2 ifname eno50332208 master team0 Connection 'team0-port2' (44d96e3a-014a-481f-9122-4ca2d3be9f7a) successfully added.
[root@localhost ~]# teamdctl team0 st setup: runner: activebackup ports: eno33554984 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0 eno50332208 link watches: link summary: up instance[link_watch_0]: name: ethtool link: up down count: 0 runner: active port: eno33554984
成功，处于活动中的网卡为 eno33554984
5.1 测试
通过down掉活动网卡测试网络是否仍然处于连通状态
测试成功。
注意： 在做网卡绑定的时候，如果发现物理网卡总是无法绑定到team0，请检查该物理网卡是否处于up状态。