--- Begin Message ---

I've been using Tim Shepard xplot together with tcptrace (srtt plots) for years 
and I'm quite happy with it.

Since xplot uses (modified) gnuplot language, I believe you meant to say that 
tcpdump2xplot was not updated?

Since tcptrace uses libpcap, I don't see that particular thing as an issue, 
really; and when tcpdump2xplot was broken before (but hardly ever used, since 
there are better workflows IMHO), is this really an issue.

Implementing a full json dumper sounds like overkill to me - and those old 
tools don't parse json anyway...

To reiterate: A number of other tools which have been improved to decode 
Accurate ECN (TCP header flags) from the full set of 12 flag bits are already 
using a shorthand notation of "A" for the AE bit; and, if they decode tcp 
streams in a stateful manner, decode the ACE field (comprised of the TCP header 
flags AE, CWR and ECE) into an octal / decimal number 0..7.

IMHO the main point to answer in this group is, if using "A" - like what 
packetdrill and wireshark are doing - would confuse anyone to mistakenly think 
the "ACK" flag - typically abbreviated "." could be confused with the "AE" flag.

I strongly believe that this is not the case, as the precedent with using "." 
for the ACK flag is in widespread use; and people mistakenly thinking the "A" 
abbreviation stands for ACK would find out the misconception extremely rapidly 
(and probably remember that much better than otherwise).

Having tcpdump use a different abbreviation would IMHO much more likely 
contribute to confusion by people using a diverse set of tools.

And yes, I am very sorry to have dropped the ball on this with the tcpdump 
project approximately 2 years ago, when updating the tooling was an area of 
very active development....

Richard Scheffenegger

-----Original Message-----
From: Michael Richardson <m...@sandelman.ca>

Scheffenegger, Richard <richard.scheffeneg...@netapp.com> wrote:
    > Tcpdump - any every tool afterwards - has been using "." for ACKs.

Hi, so there have been some tools which have parsed the tcpdump "TCP" output in 
the past, and there have been small variations in the output, and often we've 
broken those tools.
One such tool was Tim's https://man.archlinux.org/man/xplot.1.en which I think 
we broke and it never got quite fixed, and I am forever sad.

The best situation would be that you'd add a --tcp-json option and then dump 
TCP stuff in JSON, with a really long line and minimal spaces.  That might be 
too much work... it's always that situation for small incremental changes.

So I really don't have any good advice.

--- End Message ---
tcpdump-workers mailing list -- tcpdump-workers@lists.tcpdump.org
To unsubscribe send an email to tcpdump-workers-le...@lists.tcpdump.org

Reply via email to