[CentOS] After a long break, one more try at bond/bridge nics - solved

Digimer linux at alteeve.com
Sat Jan 28 03:16:53 UTC 2012


On 01/27/2012 10:03 PM, Bob Hoffman wrote:
> well...still cleaning up files to find what is and is not needed in 
> those eth, bond, and br files...
> 
> here goes..
> 
> one....
> eth files
> nm_controlled no, master=bond0, slave=yes
> no ipaddresses or any of that stuff...

Right.

> bond file..
> #1 thing....it must be name ifcfg-bond0, not just bond0

To clarify, the *file* needs to be 'ifcfg-bondX', not the device name,
which is DEVICE="bondX". The file name is used to find which files to
examine/start when network starts. The later is used when interacting
with the device itself (ie: ifup bond0).

> However, the eth files must reference solely as bond0 without the ifcfg.
> the bond file, for the moment had the ip addresses and stuff, not sure 
> if I need them there or not.

Exactly. The file is 'ifcfg-X', the device itself is just 'X'.

> (probably do not need them, but it worked with them)
> nm_controlled=no
> BRIDGE=br0
> bonding options go in this file too.

Yes, but remember to change the bond file name to 'ifcfg-vbrX'. It's
ideal to have the device name match the file name, minus the 'ifcfg-'
prefix, but it is not required.

> in etc/modprobe.d/ you need to make a file called bonding.conf
> add this line
> alias bond0 bonding

I don't use this on EL6, not sure if it's really required anymore.

> the ifcfg-br0 file, MUST be named ifcfg-br0 (or whatever your bridge is 
> name, br1, br2, etc)

Again, the *file* name *must* sort after the bond file, which
'ifcfg-br0' does *not*. The reason is that the bond interface has to be
up before the bridge.

> should contain type=Bridge
> VERY IMPORTANT YOU SPELL IT WITH A CAPITAL B, and lowercase the rest of 
> the word bridge.

Yes, this is an easy to miss point.

> (that is what was needed...go figure)
> add the ipaddresses, netmask, etc etc etc to this file
> 
> resolv.conf
> you want to add your dns servers, or for a quickie fix add
> nameserver 8.8.8.8
> nameserver 8.8.4.4
> (these are googles free dns resolvers)

You can, alternatively, define the DNS in the bridge file (or really,
any device config where you specify an IP address). I like to do this as
it puts all the stuff I need to manage into one file. For example;

vim /etc/sysconfig/network-scripts/ifcfg-vbr2

# Internet-Facing Network - Bridge
DEVICE="vbr2"
TYPE="Bridge"
BOOTPROTO="static"
IPADDR="10.255.0.1"
NETMASK="255.255.0.0"
GATEWAY="10.255.255.254"
DNS1="192.139.81.117"
DNS2="192.139.81.1"
DEFROUTE="yes"

> anyway, this is just a quickie solution, will be posting a vid of each 
> step soon..
> finally!!!!!!!!!!!
> 
> updated from 6.0 to the new version....big update...gotta wait...won't 
> let me access the VMs
> while updating...sounds scary...yikes

The update of EL6 to a new y-stream release should *not* interfere with
access to VMs. I suspect something else is causing a problem, like
running out of bandwidth or similar.

-- 
Digimer
E-Mail:              digimer at alteeve.com
Papers and Projects: https://alteeve.com



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