Hi All,

Why does this nmap scan show these ports filtered, not closed?

50420/tcp  filtered    unknown                 
50421/tcp  filtered    unknown                 
50422/tcp  open        unknown                 
50423/tcp  filtered    unknown                 
50424/tcp  filtered    unknown                 

Here are the relevant firewall rules:

LANIF=eth0
EXTIF=eth1
TCP_OPEN="22,25,53,80,113,50422"
UDP_OPEN="22,53"

iptables -P INPUT DROP
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i $EXTIF -m state --state NEW -p tcp -m multiport --dport $TCP_OPEN 
-j ACCEPT
iptables -A INPUT -i $EXTIF -m state --state NEW -p udp -m multiport --dport $UDP_OPEN 
-j ACCEPT
iptables -A INPUT -i $LANIF -m state --state NEW -j ACCEPT
iptables -A INPUT -i lo     -m state --state NEW -j ACCEPT
iptables -A INPUT -j LOG --log-prefix "INPUT-DROP "

iptables -P FORWARD DROP
iptables -A FORWARD -i $LANIF -o $EXTIF -j ACCEPT
iptables -A FORWARD -i $EXTIF -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i $EXTIF -o $LANIF -p tcp --dport 22 -m state --state 
NEW,RELATED,ESTABLISHED -j ACCEPT 
iptables -A FORWARD -i $LANIF -o $LANIF -p tcp --dport 22 -m state --state 
NEW,RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -j LOG --log-prefix "FORWARD-DROP "

iptables -t nat -A PREROUTING -p tcp --dport 50422 -j DNAT --to-destination 
192.168.0.1:22
iptables -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE

iptables -P OUTPUT ACCEPT


Also, I was wondering why a connect from the LAN port 50422 (to the
firewall) does nat to 192.168.0.1:22? It works from the internet....

Thanks,
// George


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GEORGE GEORGALIS, System Admin/Architect    cell: 347-451-8229 
Security Services, Web, Mail,            mailto:[EMAIL PROTECTED] 
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