Firewall

If you set TCP port in aMule to XX and UDP port to YY then you have to set your firewall like this:

iptables -A INPUT -p tcp --dport XX -j ACCEPT
iptables -A INPUT -p udp --dport XX+3 -j ACCEPT
iptables -A INPUT -p udp --dport YY -j ACCEPT

If you want to setup aMule behing a NAT gateway, you should add these lines to your iptables configuration script, on the gateway :

EXTIF is your external interface

EMULEPORT=5595
EMULEUDP=5595
EMULEUDP2=`expr $EMULEPORT + 3`
EMULEHOST=10.0.0.2
iptables -t nat -A PREROUTING -i $EXTIF -p tcp --destination-port $EMULEPORT -j DNAT --to-destination $EMULEHOST:$EMULEPORT
iptables -t nat -A PREROUTING -i $EXTIF -p udp --destination-port $EMULEUDP -j DNAT --to-destination $EMULEHOST:$EMULEUDP
iptables -t nat -A PREROUTING -i $EXTIF -p udp --destination-port $EMULEUDP2 -j DNAT --to-destination $EMULEHOST:$EMULEUDP2