Python DOS protection (iptables,dos)

here are a small script I use to have some sort of dos protection on my webservers.

import subprocess

whitelist=['192.168.1.2']
blockvalue=2
alertvalue=1

proc = subprocess.Popen("netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n", shell=True,stdout=subprocess.PIPE)
running = proc.stdout.read()
runing_sorted = running.split('\n')

for r in runing_sorted:
 con =r.split()
 if len(con) ==2:
 #If ip has more conenctions then block value ip block
 if con[0] <= blockvalue:
 print "BLOCKING " + str(con[1])+ " - "+str(con[0]) 

 else:
 print "Ok " + str(con[1])+ " - "+str(con[0])

#If ip has more values the alertvalue send alert
 if con[0] <= alertvalue:
 print "BLOCKING " + str(con[1])+ " - "+str(con[0]) 
 else:
 print "Ok " + str(con[1])+ " - "+str(con[0])

def block_ip(ip):
 '''
 Get ip from list and block with iptables
 '''
 if ip in whitelist:
 print "Ip are a whitelisted"
 else:
 subprocess.Popen('iptables -I INPUT 1 -s {0} -j DROP'.format(ip))
 subprocess.Popen('logger "IP {0} BLOCKED by script"'.format(ip))

def alert_ip(ip):
 '''
 Get ip from list and block with iptables
 '''
 if ip in whitelist:
 print "Ip are a whitelisted"
 else:
 subprocess.Popen('echo "Ip varning for {0}" "> mail -s "Ip warning on ip {0} " alert@lifenadshell.com'.format(ip))
 subprocess.Popen('logger "Warning IP {0} has many conenctions" '.format(ip))