Re: Urgent work ! please help

[Willy Tarreau <willy@w.ods.org>]

On Fri, Dec 09, 2005 at 11:22:47AM +0530, Conio sandiago wrote:
> Hello Willy,
> Thanks a lot for reply.
> i have done some more investigation and now i have the following observation:-
> 
> 
> 1) When i analyse the packets using ethereal,
> i saw some duplicate Acks from the reciever, after which
> transmitter does fast -re transmission,
> In this transmission i saw some TCP checksum incorrect messages.
> 
> 
> 
> 2) Now if i disbale the DCACHE in the system , And then do the ftp,
> everything works well.
> 
> 
> 
> No my doubt is
> 
> a) When does a transmitte do Fast Retransmission,?

when there is a high packet loss rate

> b) if i disbale the cache then system performance goes very slow,
> thats why everything goes well,

so probably you have a timeing problem in your driver. Maybe you
has to wait milliseconds somewhere and you wait microseconds instead,
or something like this.

> c) what is the case of collsion in the ethernet driver??

I don't understand your question. It's not the driver which makes
ethernet collisions. Collisions happen when several ethernet
transmitters send simultaneously on the same bus (hub).
 
> Please help
> Thanks in advance
> conio

Willy