[c-nsp] Fwd: 3508 / GBIC ZX / Minimum IOS

[Ryan Dorman]

One place where I have seen auto neg problems even with newer gear is  
with the use of external media converters.  Although they are  
supposed to just suck electrons in and spit lightwaves out we have  
seen instances where they are very touchy with duplex settings.

Ryan Dorman
rdorman at rdorman.net
PGP: http://rdorman.net/pgpkey.txt


On Jan 9, 2007, at 7:17 PM, Richard A Steenbergen wrote:

> On Tue, Jan 09, 2007 at 06:00:21PM -0500, Deepak Jain wrote:
>> All I can say (and I may be bitter) is that if autoneg on GigE was so
>> grand... um... why has nearly every SP found reason to disable  
>> it?? And
>> shouldn't auto neg (without neg on the other side) default to the  
>> same
>> state on both sides?? -- you know, put the "auto" in "autoneg"??
>
> In all honesty, autonegotiation problems have been effectively gone  
> for a
> very very long time now. The real problems were in the first  
> generation
> implementations on FastEthernet, and then a handful of problems  
> with GigE
> when it first came out. The continued desire to disable auto- 
> negotiation
> is senseless and a knee-jerk reaction, but SP's still do it because  
> its
> been engrained into them. In a production state auto-negotiation is
> actually left enabled, since it is capable of detecting many "one  
> side of
> a bidirectional link failure" issues. In a diagnostic state  
> however, for
> gear without light meters onboard you'll get link if you are neg  
> disabled
> regardless of the status of negotiation on the remote side, so many  
> people
> still use it for that.
>
> Fortunately the 10GE spec did what the 1GE spec should have done, and
> cleaned house of legacy things which no longer have a place in modern
> networks like "no negotiation" and "half duplex". :)
>
> -- 
> Richard A Steenbergen <ras at e-gerbil.net>       http://www.e- 
> gerbil.net/ras
> GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA  
> F8B1 2CBC)
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