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LD_LIBRARY_PATH in RedHat is LD_LIBRARY 

cat /proc/cpuinfo   #get speed/size/type cpu
getconf WORD_BIT    #returns 32 or 64 for bit proc type


Virtual Interface
ifconfig
	ifconfig eth0:1 192.168.76.24 netmask 255.255.252.0 \
						broadcast 192.168.79.255 up

Virtual Interface
Or using the iproute2 utility ip, for example:
	ip addr add 192.168.76.24 dev eth0

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Bonding or Teaming for redhat Server

Type : System
Operating System : Redhat,Fedora,Centos
Write by : Fabien FAYE

This Howto explain how to install the Bonding or the Teaming solution on a RedHat
distribution. One of the goal of the teaming and bonding solution is to use all
networks interfaces for backup or round robin solution.

The bonding need to work with a minimum of 2 NIC to have real goal.

The concept of NIC Bonding (or sometimes called NIC Teaming) is that you have two NICs
bonded together to create only one physical device.

 
Bonding schema and switch topology :

 


      |                                            |
      |port3                                  port3|
+-----+----+                                 +-----+-----+
|          |port2                      port2 |           |
| switch A +---------------------------------+ switch B  |
|          |                                 |           |
+-----+----+                                 +-----+-----+
      |port1                                  port1|
      |                 +-------+                  |
      +-----------------+ host1 +------------------+
                   eth0 +-------+ eth1

 

Before attempting to bond two NICs, i recommended to verify the integrity and
functionality of each NIC. Please check your interface status with ethtool:

#ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: g
Wake-on: g
Current message level: 0x00000007 (7)
Link detected: yes

#ethtool eth1
Settings for eth1:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: g
Wake-on: g
Current message level: 0x00000007 (7)
Link detected: yes

Now the Interface seems to be good for the configuration, we have to ckeck if you have
all kernel modules.

#modprobe --list | grep bonding

/lib/modules/2.6.*/kernel/drivers/net/bonding/bonding.ko

#modprobe --list | grep mii

/lib/modules/2.6.*/kernel/drivers/net/mii.ko

Your server seems to be ready fot the configuration of the module for a backup
connection:

#vi /etc/modprobe.conf

alias bond0 bonding
options bond0 miimon=80 mode=1

To have more information about the bonding module you have to do this command line.

In bold font you have the main status for the bonding function.

#modinfo bonding
author: Thomas Davis, tadavis@lbl.gov This e-mail address is being protected from
spambots. You need JavaScript enabled to view it and many others
description: Ethernet Channel Bonding Driver, v3.1.2
version: 3.1.2
license: GPL
srcversion: 6CD19765D6431C07199456E
depends:
vermagic: 2.6.18-53.1.4.el5xen SMP mod_unload gcc-4.1
parm: max_bonds:Max number of bonded devices (int)
parm: miimon:Link check interval in milliseconds (int)
parm: updelay:Delay before considering link up, in milliseconds (int)
parm: downdelay:Delay before considering link down, in milliseconds (int)
parm: use_carrier:Use netif_carrier_ok (vs MII ioctls) in miimon; 0 for off, 1 for on
(default) (int)
parm: mode:Mode of operation : 0 for balance-rr, 1 for active-backup, 2 for
balance-xor, 3 for broadcast, 4 for 802.3ad, 5 for balance-tlb, 6 for balance-alb
(charp)
parm: primary:Primary network device to use (charp)
parm: lacp_rate:LACPDU tx rate to request from 802.3ad partner (slow/fast) (charp)
parm: xmit_hash_policy:XOR hashing method: 0 for layer 2 (default), 1 for layer 3+4
(charp)
parm: arp_interval:arp interval in milliseconds (int)
parm: arp_ip_target:arp targets in n.n.n.n form (array of charp)
parm: arp_validate:validate src/dst of ARP probes: none (default), active, backup or
all (charp)
module_sig:
883f350474fb1b5bf23bf4d191725311298f009e2cbe4ce27b13fd747fc988615153453d50a29aff0a08158d98a7570129eb3197be02aebeaf52d9aebe

miimon is use for the monitoring of each ethX each 80 milliseconds, but you can use
also a arp_ip_target like this other configuration for this module.

#vi /etc/modprobe.conf

alias bond0 bonding
options bond0 mode=1 arp_ip_target=192.168.1.1 arp_interval=200 primary=eth0

This configuration use arp resquest on the primary interface each 200ms

Now the kernel module is configure and we have to load thoses modules :

#modprobe bonding

#modprobe mii

All modules are loaded and ready for the configuration of each NIC

Configuration of eth0:

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

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

Configuration of eth1

#vi /etc/sysconfig/network-script/ifcfg-eth1

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

Configuration of bond0

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

DEVICE=bond0
BOOTPROTO=none
ONBOOT=yes
NETMASK=255.255.255.0
IPADDR=192.168.1.5
USERCTL=no

Now to finish the installation we have to applied the network parameters.

#/etc/init.d/network restart

Your bonding is now operational.

We have to test the bonding interface :

# cat /proc/net/bonding/bond0

Ethernet Channel Bonding Driver: v3.1.2 (January 20, 2007)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: eth0
MII Status: up
MII Polling Interval (ms): 80
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth0
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:XX:XX:XX:XX:c2

Slave Interface: eth1
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:XX:XX:XX:XX:c4

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