slow bfe0, dropouts - solved

Peter Jeremy PeterJeremy at
Fri Jan 20 16:47:41 PST 2006

On Fri, 2006-Jan-20 14:04:54 -0800, Ted Faber wrote:
>The problem was that the linksys detected the card as half duplex even
>when the card was ifconfiged to be full duplex.

This is fairly normal.  I presume this is a non-managed switch - in
which case the ports will be in autonegotiate mode.  As soon as you
"ifconfig bfe0 ... media 100baseTX mediaopt full-duplex", you have
disabled autonegotiate in your host.  The switch will sense that you
are running 100Mbps but without autonegotiation, cannot detect full-
duplex and will default to half-duplex.

You _must_ either have both ends of the link set to autonegotiate
or both ends set to the same configuration.  Having autonegotiate
enabled on one end only will cause problems.

>  There is no way to
>configure teh card to be half-duplex.

No, if you specify the speed and don't specify full-duplex then you
are running half-duplex:

autonegotiate:          ifconfig bfe0 ... media autoselect
100baseTX half-duplex:  ifconfig bfe0 ... media 100baseTX
100baseTX full-duplex:  ifconfig bfe0 ... media 100baseTX mediaopt full-duplex

>  There's no obvious way to tell
>the linksys box not to try to figure out the settings of the interface.

If it's a managed switch then you can configure the interface settings
via the management interface.  Otherwise, the switch will normally be
in autonegotiate mode (assuming it supports N-way) - refer to the
switch documentation for details.

Peter Jeremy

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