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Re: load balanced nic

Shane Chrisp wrote:
> On Sun, 2008-09-28 at 12:25 +0100, ml10154@adreyer.com wrote:
>> Shane Chrisp wrote:
>>> It is quite common practise to set the ports to what you need so that
>>> the auto-negotiation does not get it wrong, in particular setting half
>>> duplex instead of full duplex. This is not so common when its 
>>> "cisco connected to cisco", but very common when its "cisco connected to
>>> some other brand".

>> Well it is common practise, but it is also one of the major problems.
>> People tend to forget these settings when they plug in other devices and
>> complain that they have "bad connectivity" or low throughput...
>> Please make sure that you do not disable the auto-negotiation on
>> Gigabit-Ports (at least when running at 1Gbit/s) - it is marked as
>> mandatory in the standard and you should rather fix the broken part that
>> doesn't understand the auto-negotiation than fiddling around with these
>> settings.

> Firstly please don't send directly to me, i am subscribed to the list.
Sorry about that.

> Second, its a bit hard to fix auto-negotiation in a vendors product such
> as a switch, firewall or router. The sad fact is that not all hardware
> plays nice with one another and you sometimes need to set the interfaces
> to prevent problems. Yes that even means Gigabit interfaces. If the
> interfaces negotiated correctly you would not configure the interface to
> a set speed, only when they do not detect each other correctly. Maybe
> that clears things up.

If a device is sold as Gigabit-Switch/-Router/-Firewall and does not
understand Gigabit auto-negotiation I would return it to the seller.

During the specification of Gigabit Ethernet they tried to avoid the
mistakes they made while defining 100Mbit/s and the auto-negotiation
process in Gb/s is pretty clear - if any "Gigabit" device can not work
with it I would expect other problems as well..


Achim Dreyer                 || http://www.adreyer.com/
Internet Security Consultant || Phone: +44 7756948229
Senior Unix & Network Admin  || RHCE, RHCA, CCNA, CCSA, CCSE, CSCE
CAcert Assurer               || JNCIS-FW

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