Wednesday, February 26, 2003

Quiet X on Port 6000 TCP

Page 260 of the second edition of Hacking Linux Exposed gives a simple trick to prevent X from listening on port 6000. If you run the X Window System using 'startx' from the command prompt, and have nothing but sshd listening, you'll find port 6000 listening once X starts:



netstat -natup

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:6000 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN


Instead launch the X server using 'startx -- -nolisten tcp'. Here's the netstat output now:



Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN


Better yet, add the following to your .bash_profile to automate this process:


alias startx='startx -- -nolisten tcp'

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