[f-nsp] 1G speed-duplex concept FESX

[Mark Tech]

Hi Thanks for the info. The reason I raised the question is that we're connecting it to a Cisco switch that doesn't have those interface options, so I was wondering what the impact would be on the Cisco if I hard coded the Foundry interface as master or slave

Regards

Mark



----- Original Message ----
From: Niels Bakker <niels=foundry-nsp at bakker..net>
To: foundry-nsp at puck.nether.net
Sent: Tuesday, December 9, 2008 1:22:39 AM
Subject: Re: [f-nsp] 1G speed-duplex concept FESX

* tdonahue at vonsystems.com (Tim Donahue) [Tue 09 Dec 2008, 00:03 CET]:
> Niels Bakker wrote:
>> * techconfig at yahoo.com (Mark Tech) [Mon 08 Dec 2008, 17:04 CET]:
>>> What is the difference/concept behind the master - slave config?
>> http://kc.forticare.com/default.asp?id=3780&Lang=1 came up in a quick google search, you may find it enlightening - especially the bit about autonegotiation being required for 1000baseT by the IEEE
> Although there may have been improvements in auto-negotiation, the following statement from the article is untrue:
> 
> 'The notion of “auto-negotiation is unreliable” can no longer be substantiated.'

In the context of GigabitEthernet...


> Considering in the past 6 months I have run into 4 endpoints that had auto-negotiation issues, I would argue that statements like this are not definitive and are not necessarily correct.  Given, all of this equipment was connecting at 100 Mb, not 1Gb, but there are times when specifying your port speed is necessary.  I would say that in 99.9% of cases auto-negotiation is reliable, but you may run into times when there are issues.

And then you come up with an example at 100baseTX.

(Have you really hooked up four thousand devices in the past 6 months?)


> (The end points had issues connecting to both Foundry and Cisco switches on different cable paths including a regular patch cable.)

So, broken end points, them being the common denominator.  I've seen the same happen; had Foundry investigate the one case I had with that, turns out end points did not actually properly implement Ethernet.

The linked article pointed out that for 1000base-X the IEEE mandated autonegotiation and interop testing of same.  That's why the claim about it working well was made.  Of course prestandard gear won't match up.


    -- Niels.

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