Re: Network Slowdowns?

[Bill Hacker <wbh@xxxxxxxxxxxxx>]

walt wrote:
> Jamie wrote:
> ...
>
> > Someone suggested changing the duplex settings on the other side, I know
> > it's running full duplex on DragonFlyBSD, but.. I don't know how to even
> > find out linux side. I'll have to research that I guess.
>
>
> ethtool works for me:
> #ethtool eth0
> Settings for eth0:
>         Supported ports: [ MII ]
>         Supported link modes:   10baseT/Half 10baseT/Full
>                                 100baseT/Half 100baseT/Full
>                                 1000baseT/Half 1000baseT/Full
>         Supports auto-negotiation: Yes
>         Advertised link modes:  10baseT/Half 10baseT/Full
>                                 100baseT/Half 100baseT/Full
>                                 1000baseT/Half 1000baseT/Full
>         Advertised auto-negotiation: Yes
>         Speed: 100Mb/s
>         Duplex: Full
>         Port: Twisted Pair
>         PHYAD: 1
>         Transceiver: internal
>         Auto-negotiation: on
>         Supports Wake-on: g
>         Wake-on: d
>         Current message level: 0x000000ff (255)
>         Link detected: yes
>
> http://sourceforge.net/projects/gkernel/

Are both ends 'local' to you?

Is there a (switching)hub in between?  Router? Just a cable?

Is anything else on the cable plant that you could disconnect for a time.

Are you in a high-noise environment? EG arc-welders, neon signs, oil-burner 
igniters, large motors w/o zero-crossing controls, even hotplates, fluorescents 
going bad, heaters, hot-water pots - and once a faulty scr in an electric steam 
iron.

Woudl loan you my Fluke 'Scopemeter', but ....distance...

- obvious next step of adding/subtracting/swapping-out, if so.

By this time, I suspect that at least one other person would have reported 
*something* similar with DFLY if it was a core code or driver issue.

As that seems not the case, it is more and more likely to be hardware/firmware, 
or something else quite specific to your environment alone.

Perchance does tcpdump show a good fast start, then a gradual clogging and slowdown?

- That was the symptom when I had SiS NIC troubles, tho' I initially blamed it 
on MTU size mismatch (other end was a 'broadand' cable-modem provider the other 
side of the island).

Bill