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Ich hätte einige Fragen bezüglich eines Firewallscriptes das ich auch der debian seite gefunden hab.
Es erscheint eine Fehlermeldung:
Ich schätze, dass es sich um den teil handelt
Außerdem, sollte man nicht eig. auch den PORT 80 reinlassen und nicht NUR rauslassen?
wenn man jetzt eine internet seite aufruft, muss man ja erst rein bevor man was rausschicken kann oder^^
Vielen dank für die antworten schonmal
Ich hätte einige Fragen bezüglich eines Firewallscriptes das ich auch der debian seite gefunden hab.
Code:
Dies ist das Beispiel-Firewallskript:
#!/bin/sh
# Simple example firewall configuration.
#
# Caveats:
# - This configuration applies to all network interfaces
# if you want to restrict this to only a given
# interface use '-i INTERFACE' in the
# iptables calls.
# - Remote access for TCP/UDP services is granted
# to any host, you probably want to restrict
# this using '--source'.
#
# chkconfig: 2345 9 91
# description: Activates/Deactivates the firewall at boot time
#
# You can test this script before applying with the
# following shell snippet, if you do not type anything
# in 10 seconds the firewall rules will be cleared.
#---------------------------------------------------------------
# while true; do test=""; read -t 20 -p "OK? " test ; \
# [ -z "$test" ] && /etc/init.d/meineFirewall clear ; done
#---------------------------------------------------------------
PATH=/bin:/sbin:/usr/bin:/usr/sbin
# Services that the system will offer to the network
TCP_SERVICES="22" # SSH only
UDP_SERVICES=""
# Services the system will use from the network
REMOTE_TCP_SERVICES="80" # web browsing
REMOTE_UDP_SERVICES="53" # DNS
# Network that will be used for remote mgmt
# (if undefined, no rules will be setup)
# NETWORK_MGMT=192.168.0.0/24
# Port used for the SSH service, define this is you have setup a
# management network but remove it from TCP_SERVICES
# SSH_PORT="22"
if ! [ -x /sbin/iptables ]; then
exit 0
fi
fw_start () {
# Input traffic:
/sbin/iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# Services
if [ -n "$TCP_SERVICES" ] ; then
for PORT in $TCP_SERVICES; do
/sbin/iptables -A INPUT -p tcp --dport ${PORT} -j ACCEPT
done
fi
if [ -n "$UDP_SERVICES" ] ; then
for PORT in $UDP_SERVICES; do
/sbin/iptables -A INPUT -p udp --dport ${PORT} -j ACCEPT
done
fi
# Remote management
if [ -n "$NETWORK_MGMT" ] ; then
/sbin/iptables -A INPUT -p tcp --src ${NETWORK_MGMT} --dport ${SSH_PORT} -j ACCEPT
else
/sbin/iptables -A INPUT -p tcp --dport ${SSH_PORT} -j ACCEPT
fi
# Remote testing
/sbin/iptables -A INPUT -p icmp -j ACCEPT
/sbin/iptables -A INPUT -i lo -j ACCEPT
/sbin/iptables -P INPUT DROP
/sbin/iptables -A INPUT -j LOG
# Output:
/sbin/iptables -A OUTPUT -j ACCEPT -o lo
/sbin/iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# ICMP is permitted:
/sbin/iptables -A OUTPUT -p icmp -j ACCEPT
# So are security package updates:
# Note: You can hardcode the IP address here to prevent DNS spoofing
# and to setup the rules even if DNS does not work but then you
# will not "see" IP changes for this service:
/sbin/iptables -A OUTPUT -p tcp -d security.debian.org --dport 80 -j ACCEPT
# As well as the services we have defined:
if [ -n "$REMOTE_TCP_SERVICES" ] ; then
for PORT in $REMOTE_TCP_SERVICES; do
/sbin/iptables -A OUTPUT -p tcp --dport ${PORT} -j ACCEPT
done
fi
if [ -n "$REMOTE_UDP_SERVICES" ] ; then
for PORT in $REMOTE_UDP_SERVICES; do
/sbin/iptables -A OUTPUT -p udp --dport ${PORT} -j ACCEPT
done
fi
# All other connections are registered in syslog
/sbin/iptables -A OUTPUT -j LOG
/sbin/iptables -A OUTPUT -j REJECT
/sbin/iptables -P OUTPUT DROP
# Other network protections
# (some will only work with some kernel versions)
echo 1 > /proc/sys/net/ipv4/tcp_syncookies
echo 0 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
echo 1 > /proc/sys/net/ipv4/conf/all/log_martians
echo 1 > /proc/sys/net/ipv4/ip_always_defrag
echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses
echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
echo 0 > /proc/sys/net/ipv4/conf/all/send_redirects
echo 0 > /proc/sys/net/ipv4/conf/all/accept_source_route
}
fw_stop () {
/sbin/iptables -F
/sbin/iptables -t nat -F
/sbin/iptables -t mangle -F
/sbin/iptables -P INPUT DROP
/sbin/iptables -P FORWARD DROP
/sbin/iptables -P OUTPUT ACCEPT
}
fw_clear () {
/sbin/iptables -F
/sbin/iptables -t nat -F
/sbin/iptables -t mangle -F
/sbin/iptables -P INPUT ACCEPT
/sbin/iptables -P FORWARD ACCEPT
/sbin/iptables -P OUTPUT ACCEPT
}
case "$1" in
start|restart)
echo -n "Starting firewall.."
fw_stop
fw_start
echo "done."
;;
stop)
echo -n "Stopping firewall.."
fw_stop
echo "done."
;;
clear)
echo -n "Clearing firewall rules.."
fw_clear
echo "done."
;;
*)
echo "Usage: $0 {start|stop|restart|clear}"
exit 1
;;
esac
exit 0
Es erscheint eine Fehlermeldung:
Code:
Starting firewall..iptables v1.4.2: invalid port/service `-j' specified
Try `iptables -h' or 'iptables --help' for more information.
done.
Ich schätze, dass es sich um den teil handelt
Code:
if [ -n "$REMOTE_TCP_SERVICES" ] ; then
for PORT in $REMOTE_TCP_SERVICES; do
/sbin/iptables -A OUTPUT -p tcp --dport ${PORT} -j ACCEPT
done
wenn man jetzt eine internet seite aufruft, muss man ja erst rein bevor man was rausschicken kann oder^^
Vielen dank für die antworten schonmal