I'm running Xvfb on a FC8 Amazon EC2 image. On occasion Xvfb will crash (unable at the moment to find out the reason for the crash), and after crashing the TCP port will appear to be orphaned. I'm unable to get a PID to kill any process that may be using it.

I'm starting Xvfb with:

Xvfb :7 -screen 0 1024x768x24 &

Examples of what I'm working with are below, the Xvfb port is (was) 6007:

# netstat -ap 
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name   
tcp        0      0 *:ssh                       *:*                         LISTEN      1894/sshd           
tcp        0      0 *:6007                      *:*                         LISTEN      -                   
tcp        0    352 ip-10-84-69-165.ec2.int:ssh c-71-194-253-238.hsd1:51689 ESTABLISHED 2981/0              
udp        0      0 *:bootpc                    *:*                                     1817/dhclient       
udp        0      0 *:bootpc                    *:*                                     1463/dhclient       
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags       Type       State         I-Node PID/Program name    Path
unix  2      [ ]         DGRAM                    871    668/udevd           @/org/kernel/udev/udevd
unix  2      [ ACC ]     STREAM     LISTENING     5385   1880/dbus-daemon    /var/run/dbus/system_bus_socket
unix  6      [ ]         DGRAM                    5353   1867/rsyslogd       /dev/log
unix  2      [ ]         DGRAM                    11861  2981/0              
unix  2      [ ]         DGRAM                    5461   1974/crond          
unix  2      [ ]         DGRAM                    5451   1904/console-kit-da 
unix  3      [ ]         STREAM     CONNECTED     5438   1880/dbus-daemon    /var/run/dbus/system_bus_socket
unix  3      [ ]         STREAM     CONNECTED     5437   1904/console-kit-da 
unix  3      [ ]         STREAM     CONNECTED     5396   1880/dbus-daemon    
unix  3      [ ]         STREAM     CONNECTED     5395   1880/dbus-daemon    
unix  2      [ ]         DGRAM                    5361   1871/rklogd


# lsof -i
COMMAND   PID USER   FD   TYPE DEVICE SIZE NODE NAME
dhclient 1463 root    3u  IPv4   4704       UDP *:bootpc 
dhclient 1817 root    4u  IPv4   5173       UDP *:bootpc 
sshd     1894 root    3u  IPv4   5414       TCP *:ssh (LISTEN)
sshd     2981 root    3u  IPv4  11825       TCP ip-10-84-69-165.ec2.internal:ssh->c-71-194-253-238.hsd1.il.comcast.net:51689 (ESTABLISHED)

Attempting to force the port closed with iptables doesn't seem to work either.

iptables -A INPUT -p tcp --dport 6007 -j DROP

I'm at a loss as to how to reclaim/free the port. From what I can tell, this port will remain in this state until the EC2 instance is shut down.

So, how can I close this port so I can restart Xvfb?