====== Ethernet Bonding ======

Note this refers to Centos / Red Hat systems. See [[linux:ubuntunetwork|Ubuntu Network Config]] and [[linux:ubuntu1804netplan|Ubuntu 18.04 Netplan]] for Ubuntu related info.
====== Linux Network ======


===== Ethernet Bonding =====

The bonding driver needs to be passed some parameters in modprobe.conf. 

  [root@gy-asp-db03 network-scripts]# cat /etc/modprobe.conf
  alias eth0 bnx2
  alias eth2 bnx2
  alias bond0 bonding
  options bond0 mode=1 miimon=100 max_bonds=2
  alias bond1 bonding
  options bond1 mode=1 miimon=100

The ''mode=1'' tells it to use active/passive, ''miimon'' sets the interval to check the mii interface to detect a failed link, and ''max_bonds'' sets the required number of bonding interfaces, default is 1.


  [root@gy-asp-db03 network-scripts]# pwd
  /etc/sysconfig/network-scripts
  [root@gy-asp-db03 network-scripts]# cat ifcfg-bond0
  DEVICE=bond0
  IPADDR=172.27.206.93
  NETMASK=255.255.255.0
  NETWORK=172.27.206.0
  ONBOOT=yes
  BOOTPROTO=none
  USERCTL=no
  
  [root@gy-asp-db03 network-scripts]# cat ifcfg-eth0
  # Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
  DEVICE=eth0
  HWADDR=1C:C1:DE:07:BB:F0
  BOOTPROTO=none
  ONBOOT=yes
  MASTER=bond0
  SLAVE=yes
  USERCTL=no
  
  [root@gy-asp-db03 network-scripts]# cat ifcfg-eth2
  # Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
  DEVICE=eth2
  HWADDR=D4:85:64:68:AA:32
  BOOTPROTO=none
  ONBOOT=yes
  HOTPLUG=no
  MASTER=bond0
  SLAVE=yes
  USERCTL=no
  
 
===== IP routing =====

Persistent routes can be set in ''/etc/sysconfig/network-scripts'' with a separate file for each interface:-

  [root@gy-asp-db03 network-scripts]# cat route-bond0 
  GATEWAY0=172.27.206.1
  NETMASK0=255.255.255.0
  ADDRESS0=172.27.205.0
  
  #.207 network not currently in use (was for ringo)
  #GATEWAY1=172.27.206.1
  #NETMASK1=255.255.255.0
  #ADDRESS1=172.27.207.0
  
This gives the following (edited) output:-

  [root@gy-asp-db03 network-scripts]# route
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  .....
  172.27.205.0    172.27.206.1    255.255.255.0   UG    0      0        0 bond0
  .....
  default         172.27.201.1    0.0.0.0         UG    0      0        0 bond1
  [root@gy-asp-db03 network-scripts]#