[CentOS] disable auto-negotiation gigabit ethernet

Tue Mar 20 16:14:08 UTC 2012
Brian Mathis <brian.mathis+centos at betteradmin.com>

On Tue, Mar 20, 2012 at 11:47 AM, sebastian <centos at secretusenet.com> wrote:
> Am 20.03.2012 16:33, schrieb m.roth at 5-cent.us:
>> Michael Simpson wrote:
>>> On 20 March 2012 14:29, sebastian<centos at secretusenet.com>  wrote:
>>>> I can not disable the auto-negotiation (eth1) on my centos 6.2 via
>>>> ethtool or /etc/sysconfig/network-scripts/ifcfg-eth1
>>> Autonegotiation is mandatory for 1000BASE-T as both sides have to work
>>> out which pairs they are going to use.
>>> Check:
>>> 1)cable
>>> 2)switchport
>>> if those are ok then you probably have a driver/NIC problem
>> Two more things:
>>     a) make sure the router/switch isn't pegged or being changed to slower
>>     b) are your cables ok for gigabit. I know this sounds absurd, but I,
>>          personally, have changed cables, and it made the difference
>>        mark
> Thanks, but is a remote-server, the server is in another datacenter. I
> can not change or check the cables/switch - and the stuff in the
> datacenter is not very useful. I'm hoping to solve the problem with
> disable the auto-negotiation.
> sebastian

As already said, you cannot disable auto-negotiation for gigabit, so
you will need to look for other ways to solve the problem.

Disabling auto-negotiation is anachronistic and no one should be doing
it anymore.  There were reportedly problems with it in the early days,
like 15 years ago, but they have all been resolved.

❧ Brian Mathis