iptables smtp, pop, ftp et www.

Bonjour a toutes et tous .
j'ai cree un fichier iptable sous debian 2.6 que j'ai mis dans init.d .
Grace a batchy celui ci se lance bien a chaque demarrage .mais je ne peut plus faire de ping sur mes interfaces
pourtant je veut juste que mes postes en (eth 1) puissent faire du pop et smtp , ftp et web .
Mon interface (eth0 ) etant celle connécté a internet .
je vous joins mon fichiers iptables.

#!/bin/sh

iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

#activation du nat
echo "1" > /proc/sys/net/ipv4/ip_forward

iptables -t nat -F
iptables -t nat -X

iptables -t nat -P PREROUTING ACCEPT
iptables -t nat -P POSTROUTING ACCEPT
iptables -t nat -P OUTPUT ACCEPT


iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE


iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT

# connexions Firewall-Internet (www)
iptables -A OUTPUT -p tcp --dport 80 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -p tcp --dport 443 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --sport 80 -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --sport 443 -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT

# connexions firewall-Internet (ftp)
iptables -A OUTPUT -p tcp --dport 21 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --sport 21 -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -o eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT

# connexions LAN-Internet (ftp)
iptables -A FORWARD -p tcp --dport 21 -i eth1 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -p tcp --sport 21 -i eth0 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -p tcp --sport 20 -i eth0 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -p tcp --dport 20 -i eth1 -o eth0 -m state --state ESTABLISHED -j ACCEPT

# connexions firewall -Internet (pop)
iptables -A OUTPUT -p tcp --dport 110 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --sport 110 -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT

# connexions LAN-Internet (pop)
iptables -A FORWARD -p tcp --dport 110 -i eth1 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -p tcp --sport 110 -i eth0 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT

# connexions firewall-Internet (imap)
iptables -A OUTPUT -p tcp --dport 143 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --sport 143 -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT

# connexions LAN-Internet (imap)
iptables -A FORWARD -p tcp --dport 143 -i eth1 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -p tcp --sport 143 -i eth0 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT

# connexions firewall-Internet (smtp)
iptables -A OUTPUT -p tcp --dport 25 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --sport 25 -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT

# connexions LAN-Internet (smtp)
iptables -A FORWARD -p tcp --dport 25 -i eth1 -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -p tcp --sport 25 -i eth0 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT