how to: Teamed NICs on PowerEdge 1950 (CentOS linux)

[Chance Reschke]

Teaming, or "trunking" or "channel bonding" network interfaces under  
RHEL is pretty straight forward.  If you wanted to trunk eth0 and  
eth1, your config files in /etc/sysconfig/network-scripts would look  
like this:

### ifcfg-bond0
DEVICE=bond0
IPADDR=192.168.1.1
NETMASK=255.255.255.0
BOOTPROTO=none
ONBOOT=yes
USERCTL=no

### ifcfg-eth0
DEVICE=eth0
MASTER=bond0
SLAVE=yes
ONBOOT=yes
USERCTL=no

### ifcfg-eth1
DEVICE=eth1
MASTER=bond0
SLAVE=yes
ONBOOT=yes
USERCTL=no

And you have to configure the bonding driver to behave as you'd like  
via /etc/modprobe.conf:

alias bond0 bonding
options bond0 mode=4
options bond0 miimon=100

The mode is important.  We use mode=4 because our tests show it  
providing the greatest increase in throughput (in fact, the other  
modes provided little or no increase).  We're using this on NFS  
servers with many clients, so you might see different performance  
results, particularly if your communication tends to be more one-to- 
one rather than one-to-many.

With mode=4 (also known as LACP or 802.3ad), you'll have to configure  
the associated switch ports to also do LACP.

Supposedly, you can bond interfaces that connect to separate  
switches, but I believe you'll have to use mode=0 (balance-rr).  I  
haven't done this myself.

Have a look at:

http://linux-net.osdl.org/index.php/ 
Bonding#High_Availability_in_a_Multiple_Switch_Topology

You'll find lots more information there than I can provide.

  - Chance

--
Chance Reschke
Biochemistry Department
University of Washington



On Oct 12, 2007, at 5:30 PM, Eugene Pik wrote:

> Is there any guide how to team 1950's onboard NICs 1950 under  
> CentOS 4 or RedHat 4?
> Will it work with any network switch or different manufacturers  
> require different teaming software/options?
> Can these NICs be connected to 2 different switches for high  
> availability?
>
> Thanks,
> Eugene Pik
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