For my notes.. If you ever wanted to check the status of a bonded interface configure in Linux (esp RHEL), you can check the status by running the following command
[root@serverxyz bin]# cat /proc/net/bonding/bond0
i.e. assuming the name of your bond interface is bond0.
Output from the command
Ethernet Channel Bonding Driver: v3.4.0 (October 7, 2008) Bonding Mode: fault-tolerance (active-backup) Primary Slave: eth3 (primary_reselect always) Currently Active Slave: eth3 MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 0 Down Delay (ms): 0 Slave Interface: eth3 MII Status: up Link Failure Count: 0 Permanent HW addr: 00:10:18:6e:b8:1a Slave Interface: eth0 MII Status: up Link Failure Count: 0 Permanent HW addr: 00:21:5e:11:34:32
The configuration files involved are
/etc/sysconfig/network-scripts/ifcfg-bond0 (Bond Interface)
DEVICE=bond0 IPADDR=10.10.40.26 NETMASK=255.255.255.0 ONBOOT=yes BOOTPROTO=none USERCTL=no GATEWAY=10.10.40.1 NETWORK=10.10.40.0 BROADCAST=10.10.40.255 TYPE=Ethernet
/etc/sysconfig/network-scripts/ifcfg-eth3 (Primary Interface)
DEVICE=eth3 BOOTPROTO=none ONBOOT=yes HWADDR=00:10:18:6e:b8:1a MASTER=bond0 SLAVE=yes TYPE=Ethernet USERCTL=no
/etc/sysconfig/network-scripts/ifcfg-eth0 (Secondary Interface)
DEVICE=eth0 HWADDR=00:21:5e:11:34:32 USERCTL=no ONBOOT=yes MASTER=bond0 SLAVE=yes BOOTPROTO=none TYPE=Ethernet