{{parent page="Linux"}}
===NIC Bonding===

Modern servers comes with more than 1 ethernet inferface, and is perfect for use with NIC bonding. Basically, load are distributed among interfaces, and in case one of the NIC or link becomes unavailable, the IP address is still served by the remaining interface.

Advanced binding (such as load balancing with cisco switch)
http://www.cyberciti.biz/howto/question/static/linux-ethernet-bonding-driver-howto.php

==Setup for ES5==
Create the bond0 if script
%%(text;ifcfg-bond0)
DEVICE=bond0
IPADDR=192.168.1.2
NETMASK=255.255.255.0
BOOTPROTO=static
ONBOOT=yes
BONDING_OPTS="mode=1 miimon=100"
MTU=9000
%%

Probe the module and bring it up
%%
modprobe bonding mode=1 miimon=100
ifup bond0
%%



==Setup for RHEL==
Go into /etc/sysconfig/network-scripts, and reference the following config files:

%%(text;ifcfg-bond0)
# bonded interface
DEVICE=bond0
BOOTPROTO=static
BROADCAST=1.2.3.255
IPADDR=1.2.3.4
NETMASK=255.255.255.0
NETWORK=1.2.3.0
ONBOOT=yes
USERCTL=no
%%

%%(text;ifcfg-eth0)
# Broadcom Corporation NetXtreme BCM5704 Gigabit Ethernet
DEVICE=eth0
USERCTL=no
ONBOOT=yes
MASTER=bond0
SLAVE=yes
BOOTPROTO=none
%%

%%(text;ifcfg-eth1)
# Broadcom Corporation NetXtreme BCM5704 Gigabit Ethernet
DEVICE=eth1
USERCTL=no
ONBOOT=yes
MASTER=bond0
SLAVE=yes
BOOTPROTO=none
%%

Then edit modules.conf so that the OS recognized /dev/bond0
%%(text;modules.conf)
alias eth0 tg3
alias eth1 tg3
alias bond0 bonding
options bond0 mode=balance-alb miimon=100
#
# For multiple nic bonding
#
# This will give you the same option on all bondings
alias bond0 bonding
alias bond1 bonding
options bonding miimon=100 mode=6 max_bonds=2
# This give you different options on each bonding
alias bond3 bonding
options bond1 -o bonding3 miimon=100 mode=1
%%

Restart networking
%%
# modprobe bonding
# service network restart
%%

==Testing==
%%(bash)
less /proc/net/bonding/bond0
ifconfig -a
%%

==LACP==
Sample output of LACP enabled link aggregation

%%
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)

Bonding Mode: IEEE 802.3ad Dynamic link aggregation
Transmit Hash Policy: layer2 (0)
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

802.3ad info
LACP rate: slow
Aggregator selection policy (ad_select): stable
Active Aggregator Info:
	Aggregator ID: 1
	Number of ports: 2
	Actor Key: 17
	Partner Key: 1000
	Partner Mac Address: 00:25:84:04:e2:34

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 00:0a:e4:14:c7:72
Aggregator ID: 1
Slave queue ID: 0

Slave Interface: eth2
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 00:0a:e4:14:c7:73
Aggregator ID: 1
Slave queue ID: 0
%%