Sunday 14 April 2013

NIC Bonding in RHEL


Steps for configuring bonding

In this document we are configuring bond0 with interfaces eth0 and eth1

Step 1- Load Kernel module
For a channel bonding interface to be valid, the kernel module must be loaded. To ensure that the module is loaded when the channel bonding interface is brought up, create a new file as root named <bonding>.conf in the /etc/modprobe.d/ directory. Note that we can name this file anything but it should with ends with a .conf extension. Insert the following line in this new file alias bond<N> bonding
Replace <N> with the interface number, such as 0. If we want to configure  configuring more than on bonding interface, For  each configured channel bonding interface, there must be a corresponding entry in  /etc/modprobe.d/<bonding>.conf file
In this example we are configuring bond0 and  file name is bonding.conf
  
[root@Nitesh modprobe.d]# cat /etc/modprobe.d/bonding.conf
  alias bond0 bonding

Step2- create channel bonding interface
We  need to create a channel bonding interface configuration file on/etc/sysconfig/network-scripts/ directory called ifcfg-bond<N> ,replacing <N> with the number for the interface, such as 0 and specify the bonding parameters on the file. Here we are creating ifcfg-bond0 file with following contents
[root@Nitesh network-scripts]# cat ifcfg-bond0
DEVICE=bond0
IPADDR=172.16.1.207
NETMASK=255.255.255.0
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
BONDING_OPTS="mode=0 miimon=1000"

Step 3- Configure Network interfaces
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
Interface eth0 configuration
 [root@Nitesh network-scripts]# cat ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
MASTER=bond0
SLAVE=yes
BOOTPROTO=none
USERCTL=no
TYPE=Ethernet
Interface eth1 configuration
[root@Nitesh network-scripts]# cat ifcfg-eth1
DEVICE=eth1
ONBOOT=yes
MASTER=bond0
SLAVE=yes
BOOTPROTO=none
TYPE=Ethernet
USERCTL=no
After configuring the interfaces we have to bring up the bond by using command
root@Nitesh network-scripts]# ifconfig bond0 up
If the bonding is correctly configured we can view the configuration using ifconfig command
[root@praji2 network-scripts]# ifconfig
bond0     Link encap:Ethernet  HWaddr 00:0C:29:69:31:C4
          inet addr:172.16.1.207  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:29:69:31: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:29:69:31: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)

To view all existing bonds we can run following command, it will list bond0
root@Nitesh network-scripts]# cat /sys/class/net/bonding_masters
bond0
To view the existing mode of bonding we can use following command
root@Nitesh network-scripts]# cat /sys/class/net/bond0/bonding/mode
balance-rr 0
For verifying bonding , we can use following command. It will list bonding details
root@Nitesh network-scripts]# cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.5.0 (November 4, 2008)

Bonding Mode: load balancing (round-robin)
MII Status: up
MII Polling Interval (ms): 1000
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth0
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:0c:29:69:31:c4

Slave Interface: eth1
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:0c:29:69:31:ce