Linux : Configuring Network Interface Bonding

For more information see /usr/share/doc/iputils-*/README.bonding

Source:
http://www.tecmint.com/create-nic-channel-bonding-in-redhat-centos-fedora/

Step 1: Creating Bonding Channel

As a root, create a new file name bonding.conf in the /etc/modprobe.d/ directory. Name can be anything you like as long as it ends with a .conf extension. Insert the following line in this new file.

alias bond0 bonding

For each configured channel bonding interface, there must be a corresponding entry in your new /etc/modprobe.d/bonding.conf file.

Step 2: Creating Channle Bonding Interface

To create a channel bonding interface, create a file in the /etc/sysconfig/network-scripts/ directory called ifcfg-bond0. The following is a sample channel bonding configuration file. (Note : IP Address may differ in your environment.)

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

DEVICE=bond0
IPADDR=192.168.1.8
NETMASK=255.255.255.0
ONBOOT=yes
BOOTPROTO=none
USERCTL=no

Step 3: Configuring Channel Bonding Interface

After the channel bonding interface is created, the network interfaces to be bound together must be configured by adding the MASTER and SLAVE directives to their configuration files. The configuration files for each of the channel-bonded interfaces can be nearly identical. For example, if two Ethernet interfaces are being channel bonded, both eth0 and eth1 may look like the following example. Edit physical interface card details as under.

For eth0

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

DEVICE=eth0
USERCTL=no
ONBOOT=yes
MASTER=bond0
SLAVE=yes
BOOTPROTO=none

For eth1

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

DEVICE=eth1
USERCTL=no
ONBOOT=yes
MASTER=bond0
SLAVE=yes
BOOTPROTO=none

The above directives are self explanatory for many system admin, however, let me explain to newbie.

1. DEVICE: Indicates what is the device name
2. USERCTL: Indicates that can user control this device(here its no)
3. ONBOOT:  Indicates that at the boot time do this device should be up?
4. MASTER: Is this device has master? Then what it is(here its bond0)
5. SLAVE: Is this device acting as slave?
6. BOOTPROTO: What about getting IP Address from DHCP? It’s set to none which indicate it’s a static IP)

Step 4: Restarting Network Service

Restart the network service and see the output of ifconfig.

# service network restart

[root@tecmint network-scripts]# ifconfig

bond0     Link encap:Ethernet  HWaddr 00:0C:21:60:30:C4
          inet addr:192.168.1.8  Bcast:172.16.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe69:31c4/64 Scope:Link
          UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1
          RX packets:19676 errors:0 dropped:0 overruns:0 frame:0
          TX packets:342 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1623240 (1.5 MiB)  TX bytes:42250 (41.2 KiB)

eth0      Link encap:Ethernet  HWaddr 00:0C:21:60:30:C4
          UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
          RX packets:10057 errors:0 dropped:0 overruns:0 frame:0
          TX packets:171 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:832257 (812.7 KiB)  TX bytes:22751 (22.2 KiB)
          Interrupt:19 Base address:0x2000

eth1      Link encap:Ethernet  HWaddr 00:0C:21:60:30:C4
          UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
          RX packets:9620 errors:0 dropped:0 overruns:0 frame:0
          TX packets:173 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:791043 (772.5 KiB)  TX bytes:20207 (19.7 KiB)
          Interrupt:19 Base address:0x2080

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:2 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:104 (104.0 b)  TX bytes:104 (104.0 b)

 Changing a Bond's Configuration
-------------------------------
        Each bond may be configured individually by manipulating the
files located in /sys/class/net/<bond name>/bonding

# pwd
/sys/class/net/bond0/bonding

# ls
active_slave    all_slaves_active  miimon        primary_reselect
ad_actor_key    arp_interval       mii_status    queue_id
ad_aggregator   arp_ip_target      min_links     resend_igmp
ad_num_ports    arp_validate       mode          slaves
ad_partner_key  downdelay          num_grat_arp  updelay
ad_partner_mac  fail_over_mac      num_unsol_na  use_carrier
ad_select       lacp_rate          primary       xmit_hash_policy

# cat mode
active-backup 1

# cat miimon
1000

# cat /etc/sysconfig/network-scripts/ifcfg-bond0
DEVICE=bond0
BOOTPROTO=static
ONBOOT=yes
IPADDR=10.100.4.162
NETMASK=255.255.240.0
BONDING_OPTS="mode=1 miimon=1000"
 

# 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: eth1
MII Status: up
MII Polling Interval (ms): 1000
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: a0:d3:c1:f3:49:81
Slave queue ID: 0

Slave Interface: eth2
MII Status: down
Speed: Unknown
Duplex: Unknown
Link Failure Count: 0
Permanent HW addr: a0:d3:c1:f3:49:82
Slave queue ID: 0

If BONDING_OPTS is not specified, bonding mode will show as :

# cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)

Bonding Mode: load balancing (round-robin)
MII Status: up
MII Polling Interval (ms): 0
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: a0:d3:c1:f3:49:fd
Slave queue ID: 0

Slave Interface: eth2
MII Status: up
Speed: Unknown
Duplex: Unknown
Link Failure Count: 0
Permanent HW addr: a0:d3:c1:f3:49:fe
Slave queue ID: 0

# cat mode
balance-rr 0

# cat miimon
0