====== Centos Networking ======

 ====== Centos Network interfaces examples ======

===== Static =====

<code>
[root@hydrogen]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 
DEVICE="eth0"
BOOTPROTO="none"
HWADDR="52:54:00:5B:C7:10"
ONBOOT="yes"
IPADDR=192.168.5.24
NETMASK=255.255.255.0
DEFROUTE=yes
[root@hydrogen]# 
</code>

<code>
$ cat /etc/sysconfig/network
HOSTNAME=server.name.pri
NETWORKING=yes
NETWORKING_IPV6=yes
GATEWAY=192.168.1.10
</code>

<code>
$ cat /etc/resolv.conf 
search mydomain.co.uk mydomain.pri
nameserver 192.168.1.1
</code>

===== DHCP =====

<code>
DEVICE="eth0"
BOOTPROTO="dhcp"
ONBOOT=yes
</code>


===== Bonding =====

<code>
$ cat /etc/sysconfig/network-scripts/ifcfg-eth[0-1]
DEVICE="eth0"
HWADDR="50:E5:49:1D:75:B1"
NM_CONTROLLED="no"
ONBOOT="yes"
BOOTPROTO=none

MASTER=bond0
SLAVE=yes
USERCTL=no




DEVICE="eth1"
HWADDR="00:10:18:27:62:98"
NM_CONTROLLED="no"
ONBOOT="yes"
BOOTPROTO=none
MASTER=bond0
SLAVE=yes
USERCTL=no
</code>

<code>
$ cat /etc/sysconfig/network-scripts/ifcfg-bond0 
DEVICE=bond0
IPADDR=192.168.1.1
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
</code>

<code>
$ cat /etc/sysconfig/network
HOSTNAME=server.name.pri
NETWORKING=yes
NETWORKING_IPV6=yes
GATEWAY=192.168.1.10
</code>

===== VLAN driver =====

This requires the 802.1q module to talk to the Cisco switch:-

  # modprobe 8021q


Not tested.




===== Bonding with VLAN driver and bridging =====

No specific switch config is required for this, but the switch ports need to be trunks not access ports.

Not tested.



===== Appendix =====

Possible duplicate stuff from Redhat 5
===== Ethernet Bonding =====

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

  [root@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@db03 network-scripts]# pwd
  /etc/sysconfig/network-scripts
  [root@gy-asp-db03 network-scripts]# cat ifcfg-bond0
  DEVICE=bond0
  IPADDR=192.168.206.93
  NETMASK=255.255.255.0
  NETWORK=192.168.206.0
  ONBOOT=yes
  BOOTPROTO=none
  USERCTL=no
  
  [root@db03 network-scripts]# cat ifcfg-eth0
  # Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
  DEVICE=eth0
  HWADDR=1C:C1:DE:07:CO:AF
  BOOTPROTO=none
  ONBOOT=yes
  MASTER=bond0
  SLAVE=yes
  USERCTL=no
  
  [root@db03 network-scripts]# cat ifcfg-eth2
  # Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
  DEVICE=eth2
  HWADDR=D4:85:64:68:AA:BB
  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@db03 network-scripts]# cat route-bond0 
  GATEWAY0=192.168.206.1
  NETMASK0=255.255.255.0
  ADDRESS0=192.168.205.0
  
  #.207 network not currently in use (was for ringo)
  #GATEWAY1=192.168.206.1
  #NETMASK1=255.255.255.0
  #ADDRESS1=192.168.207.0
  
This gives the following (edited) output:-

  [root@db03 network-scripts]# route
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  .....
  192.168.205.0    192.168.206.1    255.255.255.0   UG    0      0        0 bond0
  .....
  default         192.168.201.1    0.0.0.0         UG    0      0        0 bond1
  [root@db03 network-scripts]#