Bonded interfaces in RHEL

Here's how to create a bonded interface in RHEL 6

This bond is working in failover mode with VLAN tagging over interfaces eth0 & eth1:


ifcfg-bond0

DEVICE=bond0
TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
BONDING_OPTS="mode=1 miimon=100"

ifcfg-bond0.x  (where x is vlan number)

DEVICE=bond0.x
IPADDR=y.y.y.y
NETMASK=y.y.y.y
GATEWAY=y.y.y.y
USERCTL=no
BOOTPROTO=static
ONBOOT=yes
VLAN=yes
IPV6INIT=no

ifcfg-ethx (where x is 0 or 1)

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

Note that creating bonding.conf in /etc/modprobe.d is no longer required in the latest RHEL 6 releases.

Restart network services and the bond will be created. Make sure all previous non-bonded interfaces are destroyed before restarting network services otherwise they will interfere with the bond creation. A reboot is the easiest way to sort this out.

To check the status of a bonded interface:

cat /proc/net/bonding/bond0

Ethernet Channel Bonding Driver: v3.6.0 (September 26, 2009)

Bonding Mode: fault-tolerance (active-backup)

Primary Slave: None

Currently Active Slave: eth1

MII Status: up

MII Polling Interval (ms): 100

Up Delay (ms): 0

Down Delay (ms): 0

Slave Interface: eth1

MII Status: up

Speed: 10000 Mbps

Duplex: full

Link Failure Count: 1

Permanent HW addr: 00:9c:02:24:7c:dc

Slave queue ID: 0

Slave Interface: eth0

MII Status: up

Speed: 10000 Mbps

Duplex: full

Link Failure Count: 0

Permanent HW addr: 00:9c:02:24:7c:d8

Slave queue ID: 0

To force service to a specific interface:

 ifenslave --change-active bond0 eth0

To remove an interface from a bond

 ifenslave -d bond0 eth0

To add an interface back into a bond

 ifenslave bond0 eth0