[tg] IP fragmentation issue.

[Barbara Denny]

I didn't need to respond.  You are on the right
track...keep thinking.

barbara

--- Hugues VAN PETEGHEM <hvp at info.fundp.ac.be> wrote:
> Hi,
> 
> Yes, I'm using Ethernet and I know that the IP MTU
> over Ethernet is 1500 
> bytes. But as 'tg' is in the "application layer"
> (above "network layer" -> 
> IP), IP fragmentation must be invisible for 'tg'.
> Isn't it ?
> 
> H
> 
> On Thursday 15 April 2004 15:50, Arthur de Castro
> Callado wrote:
> > What network technology are you using? Ethernet?
> >
> > Ethernet frames must have up to 1500 bytes, no
> more. This limits the size
> > of the packet in a way that when one wants to
> transmit segments with more
> > than is allowed (bytes 1500 - headers), the
> segment will be divided into
> > pieces before sending.
> >
> > Arthur.
> >
> > On Thu, 15 Apr 2004, Hugues VAN PETEGHEM wrote:
> > > Hi all,
> > >
> > > I got an IP fragmentation problem using 'tg'.
> Here is the problem
> > > statement :
> > >
> > > ---------                                     
> ---------
> > >
> > > | pc10 |--------------------------------| pc6 |
> > >
> > > ---------10.0.0.10              
> 10.0.2.2--------
> > >
> > > I'm trying to generate a simple data flow from
> pc10 (10.0.0.10) to pc6
> > > (10.0.2.2). Here are the 'tg' input files :
> > >
> > > # pc10
> > > on 0:15 tcp 10.0.2.2.80
> > > at 5 setup
> > > at 6 arrival 0.5 length 2000
> > > packet 300
> > >
> > > # pc6
> > > on 0:15 tcp 0.0.0.0.80 server
> > > at 1 wait
> > >
> > > After a couple of minutes, I use 'dcat' to
> transform the log files in
> > > text files and here are the first lines of both
> files :
> > >
> > > # pc10
> > > (...)
> > > Event Time      Type            Address        
> Id      Length
> > >
>
-----------------------------------------------------------------
> > >
> > > 5.010170        Setup
> > > 6.509204        Transmit        10.0.2.2.80    
> 0       2000
> > > 7.009049        Transmit        10.0.2.2.80    
> 2000    2000
> > > 7.508948        Transmit        10.0.2.2.80    
> 4000    2000
> > > 8.008956        Transmit        10.0.2.2.80    
> 6000    2000
> > > (...)
> > >
> > > >From the client side, everything goes
> perfectly. Each packet is sent to
> > >
> > > 10.0.2.2:80 every 0.5 second. These packet have
> a 2000 bytes length.
> > >
> > > # pc6
> > > (...)
> > > Event Time      Type            Address        
> Id      Length
> > >
>
-----------------------------------------------------------------
> > >
> > > 0.004769        Setup
> > > 19.742468       Accept          10.0.0.10.1207 
> Association 5
> > > 21.238312       Receive         10.0.0.10.1207 
> 0       2000
> > > 21.737539       Receive         10.0.0.10.1207 
> 2000    1448
> > > 21.737888       Receive         10.0.0.10.1207 
> 3448    552
> > > 22.237457       Receive         10.0.0.10.1207 
> 4000    1448
> > > 22.237830       Receive         10.0.0.10.1207 
> 5448    552
> > > (...)
> > >
> > > >From the server side, the first packet is well
> received, but after that,
> > >
> > > everyhing is "wrong". I mean, it receive the
> data, but fragmented.
> > >
> > > I think it is a 'tg' (or 'dcat') problem. Have
> someone faced this before
> > > ? If not, could you try it and tell me if you
> have the same problem.
> > >
> > > Thanking you in advance :
> > >
> > > H
> > > --
> > > Hugues VAN PETEGHEM
> > > Institut d'Informatique - FUNDP
> > > ---------------------------------------------
> > > Web : http://www.info.fundp.ac.be/~hvp/
> > > _______________________________________________
> > > tg mailing list
> > > tg at postel.org
> > > http://www.postel.org/mailman/listinfo/tg
> 
> -- 
> Hugues VAN PETEGHEM
> Institut d'Informatique - FUNDP
> ---------------------------------------------
> Web : http://www.info.fundp.ac.be/~hvp/
> _______________________________________________
> tg mailing list
> tg at postel.org
> http://www.postel.org/mailman/listinfo/tg



	
		
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