grep, netstat, and bridging

[Chris Pressey]

On Tue, 23 Dec 2003 08:19:53 -0800 (PST)
Dave McCammon <davemac11 at yahoo.com> wrote:

> I this a feature, bug, or just some logical thing that
> grep does( or perhaps netstat)?
> 
> Scenario:
> 
> IP addresses
> comp1=xx.xx.xx.1
> comp2=xx.xx.xx.6
> comp3=xx.xx.xx.12
> 
> comp1 and comp3 run FBSD 4.9 stable
> comp2 runs FBSD 5.1-RELEASE
> 
> comp1 is a bridging firewall using ipfw
> 
> A: comp2# netstat -n |grep xx.xx.xx.1
> 
> tcp4 0 0  xx.xx.xx.6.54953 xx.xx.xx.12.3551 TIME_WAIT
> tcp4 0 0  xx.xx.xx.6.54952 xx.xx.xx.12.3551 TIME_WAIT
> tcp4 0 0  xx.xx.xx.6.22    xx.xx.xx.1.1233 
> ESTABLISHED
> 
> 
> B: comp2# netstat -n |grep xx.xx.xx.1.
> 
> tcp4 0 0  xx.xx.xx.6.54954 xx.xx.xx.12.3551 TIME_WAIT
> tcp4 0 0  xx.xx.xx.6.54953 xx.xx.xx.12.3551 TIME_WAIT
> tcp4 0 0  xx.xx.xx.6.22    xx.xx.xx.1.1233 
> ESTABLISHED
> 
> 
> C: comp2# netstat -n |grep xx.xx.xx.12
> 
> tcp4 0 0  xx.xx.xx.6.54957 xx.xx.xx.12.3551 TIME_WAIT
> tcp4 0 0  xx.xx.xx.6.54956 xx.xx.xx.12.3551 TIME_WAIT
> 
> 
> Actually..I see the same output on a cygwin machine
> behind the comp1 firewall.

>From the grep(1) man page:

  The period .  matches any single character.

Try fgrep(1) (or grep -F) instead and see if that helps?

-Chris