Re: Duplex negotiation over 100Base fibre

[Nitin Mehrotra <nmehrotra () riorey com>]

> From all my observations, if both ends are 100Base-LX (or BX or T) and are set to auto-negotiate then they will 
> negotiate to full-duplex. If one end is manually configured for full duplex and the other end is configured as auto 
> then that end _may_ end up as half-duplex.

This is particularly true when connecting a 1G port to a port configured as 100M full-duplex port. If the 1G is 
configured for auto-speed then it _will_ negotiate to 100M half-duplex resulting in traffic impact.

HTH,

Nitin

 
________________________________________
From: NANOG <nanog-bounces () nanog org> on behalf of Jason Lixfeld <jason+nanog () lixfeld ca>
Sent: Monday, February 29, 2016 11:07 AM
To: NANOG
Subject: Duplex negotiation over 100Base fibre

Hello,

My understanding is that for 1G and 10G optical networks, there is no concept of half-duplex mode, but I’m unclear 
about half duplex in the 100M optical world.  Specifically, if I connect two 100Base-LX (or BX) transceivers together, 
is there a requirement for the controller(s on either side) to select between full or half duplex, either by static 
configuration, or auto-negotiation?

Thanks!