Weyoun
15.11.05, 15:48
Hallo, ich habe mir von http://www.harry.homelinux.org/modules.php?name=iptables_Generator ein Skript generieren lassen, das mir u. a. auch Masquerading (iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE) erlauben soll. Doch irgendwie beißt sich das mit den anderen Einstellungen. Ich kann auf dem Router bei aktivierten IPTables surfen, doch die Clients können das nicht. Anpingen des Servers geht nur bei gestoppter Firewall. :P
Irgendwelche Tipps? Bevor ich den Fehler finde, habe ich sicher bereits mein eigenes Skript zusammengebastelt, aber ich lass euch mal einen Blick riskieren:
#!/bin/bash
# ---------------------------------------------------------------------
# Linux-iptables-Firewallskript, Copyright (c) 2005 under the GPL
# Autogenerated by iptables Generator v1.20 (c) 2002-2005 by Harald Bertram
# Please visit http://www.harry.homelinux.org for new versions of
# the iptables Generator (c).
#
# This Script was generated by request from:
# huebner_mark@web.de on: 2005-11-15 12:43.45 MET.
#
# If you have questions about the iptables Generator or about
# your Firewall-Skript feel free to take a look at out website or
# send me an E-Mail to webmaster@harry.homelinux.org.
#
# My special thanks are going to Lutz Heinrich (trinitywork at hotmail dot com)
# who made lots of Beta-Testing and gave me lots of well qualified
# Feedback that made me able to improve the iptables Generator.
# --------------------------------------------------------------------
#
### BEGIN INIT INFO
# Provides: IP-Paketfilter
# Required-Start: $network $local_fs
# Required-Stop: $local_fs
# Default-Start: 3 5
# Default-Stop: 0 1 2 4 6
# Short-Description: Harry's IP-Paketfilter
# Description: Harry's IP-Paketfilter provides reasonable
# IP-Security for Home-Computers and small networks
### END INIT INFO
#
case "$1" in
start)
echo "Starte IP-Paketfilter"
# iptables-Modul
modprobe ip_tables
# Connection-Tracking-Module
modprobe ip_conntrack
# Das Modul ip_conntrack_irc ist erst bei Kerneln >= 2.4.19 verfuegbar
modprobe ip_conntrack_irc
modprobe ip_conntrack_ftp
# Tabelle flushen
iptables -F
iptables -t nat -F
iptables -t mangle -F
iptables -X
iptables -t nat -X
iptables -t mangle -X
# Default-Policies setzen
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP
# MY_REJECT-Chain
iptables -N MY_REJECT
# MY_REJECT fuellen
iptables -A MY_REJECT -p tcp -m limit --limit 7200/h -j LOG --log-prefix "REJECT TCP "
iptables -A MY_REJECT -p tcp -j REJECT --reject-with tcp-reset
iptables -A MY_REJECT -p udp -m limit --limit 7200/h -j LOG --log-prefix "REJECT UDP "
iptables -A MY_REJECT -p udp -j REJECT --reject-with icmp-port-unreachable
iptables -A MY_REJECT -p icmp -m limit --limit 7200/h -j LOG --log-prefix "DROP ICMP "
iptables -A MY_REJECT -p icmp -j DROP
iptables -A MY_REJECT -m limit --limit 7200/h -j LOG --log-prefix "REJECT OTHER "
iptables -A MY_REJECT -j REJECT --reject-with icmp-proto-unreachable
# MY_DROP-Chain
iptables -N MY_DROP
iptables -A MY_DROP -m limit --limit 7200/h -j LOG --log-prefix "PORTSCAN DROP "
iptables -A MY_DROP -j DROP
# Alle verworfenen Pakete protokollieren
iptables -A INPUT -m state --state INVALID -m limit --limit 7200/h -j LOG --log-prefix "INPUT INVALID "
iptables -A OUTPUT -m state --state INVALID -m limit --limit 7200/h -j LOG --log-prefix "OUTPUT INVALID "
# Korrupte Pakete zurueckweisen
iptables -A INPUT -m state --state INVALID -j DROP
iptables -A OUTPUT -m state --state INVALID -j DROP
# Stealth Scans etc. DROPpen
# Keine Flags gesetzt
iptables -A INPUT -p tcp --tcp-flags ALL NONE -j MY_DROP
# SYN und FIN gesetzt
iptables -A INPUT -p tcp --tcp-flags SYN,FIN SYN,FIN -j MY_DROP
# SYN und RST gleichzeitig gesetzt
iptables -A INPUT -p tcp --tcp-flags SYN,RST SYN,RST -j MY_DROP
# FIN und RST gleichzeitig gesetzt
iptables -A INPUT -p tcp --tcp-flags FIN,RST FIN,RST -j MY_DROP
# FIN ohne ACK
iptables -A INPUT -p tcp --tcp-flags ACK,FIN FIN -j MY_DROP
# PSH ohne ACK
iptables -A INPUT -p tcp --tcp-flags ACK,PSH PSH -j MY_DROP
# URG ohne ACK
iptables -A INPUT -p tcp --tcp-flags ACK,URG URG -j MY_DROP
# Loopback-Netzwerk-Kommunikation zulassen
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
# Connection-Tracking aktivieren
iptables -A OUTPUT -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# HTTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 80 -j ACCEPT
# SMTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 25 -j ACCEPT
# POP3
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 110 -j ACCEPT
# IMAP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 143 -j ACCEPT
# DNS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 53 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 53 -j ACCEPT
# SMB/CIFS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 137 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 138 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 139 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 445 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 137 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 138 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 139 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 445 -j ACCEPT
# SSH
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 22 -j ACCEPT
# EDONKEY
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 4661 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 4662 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 4663 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 4665 -j ACCEPT
# OPENVPN_V1
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5000 -j ACCEPT
# ICMP Echo-Request (ping) zulassen und beantworten
iptables -A INPUT -m state --state NEW -p icmp --icmp-type echo-request -j ACCEPT
# LAN-Zugriff auf eth0
iptables -A INPUT -m state --state NEW -i eth0 -j ACCEPT
# Default-Policies mit REJECT
iptables -A INPUT -j MY_REJECT
iptables -A OUTPUT -j MY_REJECT
# Masquerading
iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE
# SYN-Cookies
echo 1 > /proc/sys/net/ipv4/tcp_syncookies 2> /dev/null
# Stop Source-Routing
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/accept_source_route 2> /dev/null; done
# Stop Redirecting
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/accept_redirects 2> /dev/null; done
# Reverse-Path-Filter
for i in /proc/sys/net/ipv4/conf/*; do echo 2 > $i/rp_filter 2> /dev/null; done
# Log Martians
for i in /proc/sys/net/ipv4/conf/*; do echo 1 > $i/log_martians 2> /dev/null; done
# BOOTP-Relaying ausschalten
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/bootp_relay 2> /dev/null; done
# Proxy-ARP ausschalten
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/proxy_arp 2> /dev/null; done
# Ungültige ICMP-Antworten ignorieren
echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses 2> /dev/null
# ICMP Echo-Broadcasts ignorieren
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts 2> /dev/null
# Max. 500/Sekunde (5/Jiffie) senden
echo 5 > /proc/sys/net/ipv4/icmp_ratelimit
# Speicherallozierung und -timing für IP-De/-Fragmentierung
echo 262144 > /proc/sys/net/ipv4/ipfrag_high_thresh
echo 196608 > /proc/sys/net/ipv4/ipfrag_low_thresh
echo 30 > /proc/sys/net/ipv4/ipfrag_time
# TCP-FIN-Timeout zum Schutz vor DoS-Attacken setzen
echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout
# Maximal 3 Antworten auf ein TCP-SYN
echo 3 > /proc/sys/net/ipv4/tcp_retries1
# TCP-Pakete maximal 15x wiederholen
echo 15 > /proc/sys/net/ipv4/tcp_retries2
;;
stop)
echo "Stoppe IP-Paketfilter"
# Tabelle flushen
iptables -F
iptables -t nat -F
iptables -t mangle -F
iptables -X
iptables -t nat -X
iptables -t mangle -X
# Default-Policies setzen
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
;;
status)
echo "Tabelle filter"
iptables -L -vn
echo "Tabelle nat"
iptables -t nat -L -vn
echo "Tabelle mangle"
iptables -t mangle -L -vn
;;
*)
echo "Fehlerhafter Aufruf"
echo "Syntax: $0 {start|stop|status}"
exit 1
;;
esac
Irgendwelche Tipps? Bevor ich den Fehler finde, habe ich sicher bereits mein eigenes Skript zusammengebastelt, aber ich lass euch mal einen Blick riskieren:
#!/bin/bash
# ---------------------------------------------------------------------
# Linux-iptables-Firewallskript, Copyright (c) 2005 under the GPL
# Autogenerated by iptables Generator v1.20 (c) 2002-2005 by Harald Bertram
# Please visit http://www.harry.homelinux.org for new versions of
# the iptables Generator (c).
#
# This Script was generated by request from:
# huebner_mark@web.de on: 2005-11-15 12:43.45 MET.
#
# If you have questions about the iptables Generator or about
# your Firewall-Skript feel free to take a look at out website or
# send me an E-Mail to webmaster@harry.homelinux.org.
#
# My special thanks are going to Lutz Heinrich (trinitywork at hotmail dot com)
# who made lots of Beta-Testing and gave me lots of well qualified
# Feedback that made me able to improve the iptables Generator.
# --------------------------------------------------------------------
#
### BEGIN INIT INFO
# Provides: IP-Paketfilter
# Required-Start: $network $local_fs
# Required-Stop: $local_fs
# Default-Start: 3 5
# Default-Stop: 0 1 2 4 6
# Short-Description: Harry's IP-Paketfilter
# Description: Harry's IP-Paketfilter provides reasonable
# IP-Security for Home-Computers and small networks
### END INIT INFO
#
case "$1" in
start)
echo "Starte IP-Paketfilter"
# iptables-Modul
modprobe ip_tables
# Connection-Tracking-Module
modprobe ip_conntrack
# Das Modul ip_conntrack_irc ist erst bei Kerneln >= 2.4.19 verfuegbar
modprobe ip_conntrack_irc
modprobe ip_conntrack_ftp
# Tabelle flushen
iptables -F
iptables -t nat -F
iptables -t mangle -F
iptables -X
iptables -t nat -X
iptables -t mangle -X
# Default-Policies setzen
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP
# MY_REJECT-Chain
iptables -N MY_REJECT
# MY_REJECT fuellen
iptables -A MY_REJECT -p tcp -m limit --limit 7200/h -j LOG --log-prefix "REJECT TCP "
iptables -A MY_REJECT -p tcp -j REJECT --reject-with tcp-reset
iptables -A MY_REJECT -p udp -m limit --limit 7200/h -j LOG --log-prefix "REJECT UDP "
iptables -A MY_REJECT -p udp -j REJECT --reject-with icmp-port-unreachable
iptables -A MY_REJECT -p icmp -m limit --limit 7200/h -j LOG --log-prefix "DROP ICMP "
iptables -A MY_REJECT -p icmp -j DROP
iptables -A MY_REJECT -m limit --limit 7200/h -j LOG --log-prefix "REJECT OTHER "
iptables -A MY_REJECT -j REJECT --reject-with icmp-proto-unreachable
# MY_DROP-Chain
iptables -N MY_DROP
iptables -A MY_DROP -m limit --limit 7200/h -j LOG --log-prefix "PORTSCAN DROP "
iptables -A MY_DROP -j DROP
# Alle verworfenen Pakete protokollieren
iptables -A INPUT -m state --state INVALID -m limit --limit 7200/h -j LOG --log-prefix "INPUT INVALID "
iptables -A OUTPUT -m state --state INVALID -m limit --limit 7200/h -j LOG --log-prefix "OUTPUT INVALID "
# Korrupte Pakete zurueckweisen
iptables -A INPUT -m state --state INVALID -j DROP
iptables -A OUTPUT -m state --state INVALID -j DROP
# Stealth Scans etc. DROPpen
# Keine Flags gesetzt
iptables -A INPUT -p tcp --tcp-flags ALL NONE -j MY_DROP
# SYN und FIN gesetzt
iptables -A INPUT -p tcp --tcp-flags SYN,FIN SYN,FIN -j MY_DROP
# SYN und RST gleichzeitig gesetzt
iptables -A INPUT -p tcp --tcp-flags SYN,RST SYN,RST -j MY_DROP
# FIN und RST gleichzeitig gesetzt
iptables -A INPUT -p tcp --tcp-flags FIN,RST FIN,RST -j MY_DROP
# FIN ohne ACK
iptables -A INPUT -p tcp --tcp-flags ACK,FIN FIN -j MY_DROP
# PSH ohne ACK
iptables -A INPUT -p tcp --tcp-flags ACK,PSH PSH -j MY_DROP
# URG ohne ACK
iptables -A INPUT -p tcp --tcp-flags ACK,URG URG -j MY_DROP
# Loopback-Netzwerk-Kommunikation zulassen
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
# Connection-Tracking aktivieren
iptables -A OUTPUT -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# HTTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 80 -j ACCEPT
# SMTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 25 -j ACCEPT
# POP3
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 110 -j ACCEPT
# IMAP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 143 -j ACCEPT
# DNS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 53 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 53 -j ACCEPT
# SMB/CIFS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 137 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 138 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 139 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 445 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 137 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 138 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 139 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 445 -j ACCEPT
# SSH
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 22 -j ACCEPT
# EDONKEY
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 4661 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 4662 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 4663 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 4665 -j ACCEPT
# OPENVPN_V1
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5000 -j ACCEPT
# ICMP Echo-Request (ping) zulassen und beantworten
iptables -A INPUT -m state --state NEW -p icmp --icmp-type echo-request -j ACCEPT
# LAN-Zugriff auf eth0
iptables -A INPUT -m state --state NEW -i eth0 -j ACCEPT
# Default-Policies mit REJECT
iptables -A INPUT -j MY_REJECT
iptables -A OUTPUT -j MY_REJECT
# Masquerading
iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE
# SYN-Cookies
echo 1 > /proc/sys/net/ipv4/tcp_syncookies 2> /dev/null
# Stop Source-Routing
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/accept_source_route 2> /dev/null; done
# Stop Redirecting
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/accept_redirects 2> /dev/null; done
# Reverse-Path-Filter
for i in /proc/sys/net/ipv4/conf/*; do echo 2 > $i/rp_filter 2> /dev/null; done
# Log Martians
for i in /proc/sys/net/ipv4/conf/*; do echo 1 > $i/log_martians 2> /dev/null; done
# BOOTP-Relaying ausschalten
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/bootp_relay 2> /dev/null; done
# Proxy-ARP ausschalten
for i in /proc/sys/net/ipv4/conf/*; do echo 0 > $i/proxy_arp 2> /dev/null; done
# Ungültige ICMP-Antworten ignorieren
echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses 2> /dev/null
# ICMP Echo-Broadcasts ignorieren
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts 2> /dev/null
# Max. 500/Sekunde (5/Jiffie) senden
echo 5 > /proc/sys/net/ipv4/icmp_ratelimit
# Speicherallozierung und -timing für IP-De/-Fragmentierung
echo 262144 > /proc/sys/net/ipv4/ipfrag_high_thresh
echo 196608 > /proc/sys/net/ipv4/ipfrag_low_thresh
echo 30 > /proc/sys/net/ipv4/ipfrag_time
# TCP-FIN-Timeout zum Schutz vor DoS-Attacken setzen
echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout
# Maximal 3 Antworten auf ein TCP-SYN
echo 3 > /proc/sys/net/ipv4/tcp_retries1
# TCP-Pakete maximal 15x wiederholen
echo 15 > /proc/sys/net/ipv4/tcp_retries2
;;
stop)
echo "Stoppe IP-Paketfilter"
# Tabelle flushen
iptables -F
iptables -t nat -F
iptables -t mangle -F
iptables -X
iptables -t nat -X
iptables -t mangle -X
# Default-Policies setzen
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
;;
status)
echo "Tabelle filter"
iptables -L -vn
echo "Tabelle nat"
iptables -t nat -L -vn
echo "Tabelle mangle"
iptables -t mangle -L -vn
;;
*)
echo "Fehlerhafter Aufruf"
echo "Syntax: $0 {start|stop|status}"
exit 1
;;
esac