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

[Tassos Chatzithomaoglou]

Gert Doering wrote on 9/1/2007 9:48 πμ:
> Hi,
> 
> On Mon, Jan 08, 2007 at 11:30:47PM -0500, Deepak Jain wrote:
>> However, the 3508 does not show "link". All its interfaces are showing 
>> "down/down" and the lights are all dead (though they light up on power 
>> up test). Power up test shows no errors or anomalies.
> 
> You might need to play with port negotiation - I've never understood what
> autonegotiation is *good* for on GigE fiber ports ("single possible speed,
> always full duplex") but if one side is set to negotiate, and the other
> side to *not* do it, you won't get a link.  BTDT.
> 

According to Cisco, GigE has an autonegotiation procedure that is more extensive than what is used for 10/100 Mbps Ethernet.
This procedure negotiates flow control, duplex mode, and remote fault information, so disabling it, may hide link drops and other 
physical layer problems. Flow control & duplex can also be managed independently (if allowed), so i guess remote fault information 
is the one that actually matters.

--
Tassos

> I'm not sure what the correct command on the 3508 is, but it's always
> something along the lines of
> 
>   [no] negotiation auto
>   [no] switchport nonegotiate
>   [no] speed nonegotiate
> 
> - check the online help...
> 
> gert
>