l i n u x - u s e r s - g r o u p - o f - d a v i s
L U G O D
 
Next Meeting:
November 4: Social gathering
Next Installfest:
TBD
Latest News:
Oct. 24: LUGOD election season has begun!
Page last updated:
2002 Feb 11 22:32

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
Re: [vox-tech] tcpdump help was: packet sniffer help
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] tcpdump help was: packet sniffer help



On Mon, Feb 11, 2002 at 05:46:01PM -0800, Peter Jay Salzman wrote:
> joel, i'm having trouble with tcpdump.  can you clear something up for
> me?   suppose i wanted to look at two (destination) ports at the same
> time.  this doesn't work:
> 
> 	tcpdump -i eth0 dst port 25906 && dst port 27950
> 
> i think the shell is trying to interpret the &&.

I usually use "and", "or", and "not" instead of the symbols so that the
shell won't try to interpret them.

But are you sure that 'and' is really the logic that you want?  Your
rule will only match packets which are destined for both ports 25906 AND
27950 (which is impossible).  It seems like you should be using "or" so
that the rule will match packets destined for either port.

> also, is there a way to look at the packet payload?  i'm not much
> interested in the raw packet themselves.   any way to peek at the
> contents using tcpdump?

I'm not sure about this.  I know that -v, -vv, and -vvv print out
additional information about each packet, but I haven't really used them
much.  Ethereal is a pretty useful tool if you want to view the packet
contents since it can reconstruct packet sequences.

Matt

-- 

*************************************************
* Matt Roper <matt@mattrope.com>                *
* http://www.mattrope.com                       *
* PGP Key: http://www.mattrope.com/mattrope.asc *
*************************************************
_______________________________________________
vox-tech mailing list
vox-tech@lists.lugod.org
http://lists.lugod.org/mailman/listinfo/vox-tech



LinkedIn
LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
facebook
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
Sunset Systems
Who graciously hosts our website & mailing lists!