[CentOS] how to enable Flow Control on CentOS?

Les Mikesell lesmikesell at gmail.com
Mon Jul 11 03:08:36 UTC 2011

On 7/9/11 12:18 PM, Giles Coochey wrote:
> On 09/07/2011 01:06, Les Mikesell wrote:
>> Turning off negotiation pretty much guarantees problems if anything changes at
>> the other end or you use an unmanaged switch. And the gigabit spec requires
>> auto-negotiation.
> Let me make it clear - auto-negotiation only works if auto-negotiation is
> configured on both sides.

Errr, auto-negotiation is normally the default.  So it to be more clear, it 
works unless you break it by changing it only on one side.

 > It does not work if one side hard codes the speed and
> duplex. Both sides have to be set for it to negotiate. Agreeing on speed and
> duplex ensures that it will work.

That means both sides have to know about each other, whereas one side is 
networking equipment and the other is often host equipment, managed by different 
sets of people.  And there is no need for them to agree/disagree or waste time 
thinking about it at all.  The defaults should work.

> If something is going to change on the remote end without you knowing, or your
> provider is using an unmanaged switch then it's time to change provider :-) -
> they obviously are cheapskates and don't have any change management control on
> their systems.

I'm not talking about 'providers', I'm talking about the people who set up 
network equipment vs. people who manage hosts.  If the people managing the 
network equipment say negotiation needs to be off they are wrong, even if they 
claim to be the authority in the debate.

> Gigabit is different.

No, the default of auto-negotiating  works there too.

   Les Mikesell
    lesmikesell at gmail.com

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