[freebsd-questions] Bandwidth Troubleshooting

[Howard Jones]

Gunter Wambaugh wrote:
>
> The sad thing is that I read somewhere (probably on this list) that 
> *forcing* 100 would
> _increase_ performance because there wouldn't be any auto 
> negotiating.   I added it to
> my rc.conf, but later I decided that it didn't help any so I ran 
> ifconfig fxp0 media autoselect,
> but failed to change my rc.conf back!  Now I have learned that not 
> only did it not improve performance, it seriously
>  crippled it.  Thanks for helping me track that down.
If you have two auto-negotiating devices and one is hard-set to a 
particular speed/duplex, then the other should always choose 100/Half. 
It doesn't try and auto-detect what the other one is speaking. It's 
supposed to be a *negotiation* and if one party doesn't talk, then the 
other one defaults.

So if you can get your Linksys to force the port speed, then you can 
safely do it on your server, otherwise auto-negotiation should negotiate 
100/Full anyway if both can do it.

Here's a better explanation than mine:
   http://www.cites.uiuc.edu/network/autosense.html#how

I lost count of how many times this has bitten me in various shapes and 
forms.

Howie