TCP tools.

k claffy kc at caida.org
Sat Jul 17 00:08:41 UTC 1999



forrest

http://www.caida.org/Tools/taxonomy.html
suggests that the closest you can get right now 
is creative combination of tcpdump, tcptrace and xplot.  

  tcpdump       ftp://ftp.ee.lbl.gov/
  tcptrace      http://jarok.cs.ohiou.edu/software/tcptrace/tcptrace.html
  xplot         ftp://mercury.lcs.mit.edu/pub/shep/

if there is a free package that does everything 
including diagnosing the problem, we havent found it yet.
(good windmill, tho.)

if you need tcpdump at or above OC-3,
you'll need something like
	http://www.caida.org/Tools/Coral/
(not yet for the faint of heart)

also
	http://www.psc.edu/networking/tcp_friendly.html
	http://www.psc.edu/networking/perf_tune.html
might be of interest to you in vendor.appeals

sorry the news isn't better
maybe give it some time
(actually, give it some coders)
k


On Fri, Jul 16, 1999 at 03:36:35AM -0600, Forrest W. Christian wrote:
  
  I really can't think of a better place to ask this, so If anyone has any
  ideas of a place better suited please let me know (no flames please).
  
  I'm looking for a (free or quite inexpensive) tool to help diagnose some
  bizzare TCP problems we're having with some TCP flows stalling exactly 32k
  into the transfer.  This isn't the same file and it's almost exacly 32k
  each time... but I digress.
  
  Is there a tool out there that can sniff a TCP flow and do some basic
  analysis such as missed acks, duplicate packets, Window Sizes, etc. etc. 
  Mainly, I'm looking at something which can compare what it sees with some
  semblance of a normal flow and pick out "errors".  Other tools to track
  down stalls would be helpful also.  No, I'm not looking for ping tools or
  flood tools, etc., but instead something which can help me determine why
  this particular TCP implementation is stalling consistently in serveral
  different environments so I can go yell at the vendor.
  
  I realize that most if not all packet sniffers will provide the
  information neccessary to do this analysis by hand,  but picking apart
  multiple flows bit by bit can be tedious and error prone, and not
  something I particularly want to do if there is an easier way.
  
  Thanks for all pointers.
  
  - Forrest W. Christian (forrestc at imach.com) KD7EHZ
  ----------------------------------------------------------------------
  iMach, Ltd., P.O. Box 5749, Helena, MT 59604      http://www.imach.com
  Solutions for your high-tech problems.                  (406)-442-6648
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