PRoblem with UDP sockets

Pierre Blanchet Pierre.Blanchet at solsoft.fr
Fri Feb 16 16:26:36 CET 2001


On February 16 2001 at 9:28, 
	"Steve Holden" <sholden at holdenweb.com> wrote:
> "Pierre Blanchet" <Pierre.Blanchet at solsoft.fr> wrote in message
> news:mailman.982332924.15258.python-list at python.org...
> > I'm trying to code a TFTP client with python 1.5.2 under
> > Linux.
> >
> > I cannot find a way to send UDP packets shorter than 14
> > bytes.
> >
> > By example, if i try to send (using sendto) the string ' 0
> > 4 0 1', i get on the wire '0 4 0 1 1 1 1 1 1 1 1 1 1 1 1' althougth
> > sendto tell me it has send 4 bytes.
> >
> > Do i do something wrong ? Is there a bug in python in Linux
> > ?
> >
> > TIA,
> >
> > Pierre.
> >
> Have you checked the data length in the UPD header? Wondered whether this
> might be more to do with the minimum Ethernet frame size...
> 

	Nevermind. The bug was mine.

	Actually now my TFTPclient works :) But my packets are 
still longer than i need.

	But you were right, the minimum size of an ethernet packet 
is 60 ( as shown by ethereal) and there is a need for padding (in 
my case 14 bytes in the "trailer").

	Thanks Steve for your help,

	Pierre.

-- 
Pierre Blanchet		 				  Support Engineer
http://www.solsoft.com				Pierre.Blanchet at solsoft.fr
Tel.: +33 147 15 55 00                               Fax: +33 147 15 55 09






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