MisterX
09.03.03, 13:31
Hallo,
ich habe mal eine frage bezüglich der Iptables. Vor einiger Zeit habe ich mir auf der homepage http://www.harry.homelinux.org/ die Iptables Generieren. Leider funktionieren die nicht richtig, ich kam auf einige Seiten nicht drauf z.B. www.ebay.de oder so. Jedenfalls habe ich eine mail an den Webmaster geschickt und bekam prompt hilfe. Es wurde ein zusatz reingeschrieben, jedoch kann ich die Iptables jetzt leider nicht mehr Starten! (Fehler: bad Interpreter) Woran kann das liegen?
Das es die Homepage wohl nicht mehr gibt, wollte ich fragen ob mir jemand von euch weiterhelfen kann!
Gruß Markus
#!/bin/bash
# ---------------------------------------------------------------------
# Linux-iptables-Firewallskript, Copyright (c) 2003 under the GPL
# Autogenerated by iptables Generator v1.15 (c) 2002 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:
# Markus2212@web.de on: 2003-2-9 23:13.43 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@hotmail.com) who
# made lots of Beta-Testing and gave me lots of well qualified
# Feedback that made me able to improve the iptables Generator.
# --------------------------------------------------------------------
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 "
iptables -A FORWARD -m state --state INVALID -m limit --limit 7200/h -j LOG --log-prefix "FORWARD INVALID "
# Korrupte Pakete zurueckweisen
iptables -A INPUT -m state --state INVALID -j DROP
iptables -A OUTPUT -m state --state INVALID -j DROP
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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 FORWARD -i ! ppp0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# Max. Segment-Size für das Forwarding anpassen
iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
# HTTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 80 -j ACCEPT
# HTTPS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 443 -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
# POP3S
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 995 -j ACCEPT
# IMAP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 143 -j ACCEPT
# IMAPS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 993 -j ACCEPT
# NNTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 119 -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
# FTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 21 -j ACCEPT
# SMB
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 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
# SSH
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 22 -j ACCEPT
# MYSQL
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 3306 -j ACCEPT
# NTP
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 123 -j ACCEPT
# IRC
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 6667 -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
# TELNET
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 23 -j ACCEPT
# BZFLAG
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 5155 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5155 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 5156 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5156 -j ACCEPT
# HALF-LIFE
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 6000:6003 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 7001:7002 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 27005 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 27010 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 27015:27016 -j ACCEPT
# IPSEC
iptables -A INPUT -i ppp0 -p 50 -j ACCEPT
iptables -A INPUT -i ppp0 -p 51 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 500 -j ACCEPT
# OPENVPN
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5000 -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
iptables -A FORWARD -j MY_REJECT
# Routing
echo 1 > /proc/sys/net/ipv4/ip_forward 2> /dev/null
# 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
# Auskommentiert, da IPSEC mit RP_Filter nicht funktioniert!
# 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
echo "Deaktiviere IP-Routing"
echo 0 > /proc/sys/net/ipv4/ip_forward
# 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
ich habe mal eine frage bezüglich der Iptables. Vor einiger Zeit habe ich mir auf der homepage http://www.harry.homelinux.org/ die Iptables Generieren. Leider funktionieren die nicht richtig, ich kam auf einige Seiten nicht drauf z.B. www.ebay.de oder so. Jedenfalls habe ich eine mail an den Webmaster geschickt und bekam prompt hilfe. Es wurde ein zusatz reingeschrieben, jedoch kann ich die Iptables jetzt leider nicht mehr Starten! (Fehler: bad Interpreter) Woran kann das liegen?
Das es die Homepage wohl nicht mehr gibt, wollte ich fragen ob mir jemand von euch weiterhelfen kann!
Gruß Markus
#!/bin/bash
# ---------------------------------------------------------------------
# Linux-iptables-Firewallskript, Copyright (c) 2003 under the GPL
# Autogenerated by iptables Generator v1.15 (c) 2002 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:
# Markus2212@web.de on: 2003-2-9 23:13.43 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@hotmail.com) who
# made lots of Beta-Testing and gave me lots of well qualified
# Feedback that made me able to improve the iptables Generator.
# --------------------------------------------------------------------
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 "
iptables -A FORWARD -m state --state INVALID -m limit --limit 7200/h -j LOG --log-prefix "FORWARD INVALID "
# Korrupte Pakete zurueckweisen
iptables -A INPUT -m state --state INVALID -j DROP
iptables -A OUTPUT -m state --state INVALID -j DROP
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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
iptables -A FORWARD -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 FORWARD -i ! ppp0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# Max. Segment-Size für das Forwarding anpassen
iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
# HTTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 80 -j ACCEPT
# HTTPS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 443 -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
# POP3S
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 995 -j ACCEPT
# IMAP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 143 -j ACCEPT
# IMAPS
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 993 -j ACCEPT
# NNTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 119 -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
# FTP
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 21 -j ACCEPT
# SMB
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 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
# SSH
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 22 -j ACCEPT
# MYSQL
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 3306 -j ACCEPT
# NTP
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 123 -j ACCEPT
# IRC
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 6667 -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
# TELNET
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 23 -j ACCEPT
# BZFLAG
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 5155 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5155 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 5156 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5156 -j ACCEPT
# HALF-LIFE
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 6000:6003 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p tcp --dport 7001:7002 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 27005 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 27010 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 27015:27016 -j ACCEPT
# IPSEC
iptables -A INPUT -i ppp0 -p 50 -j ACCEPT
iptables -A INPUT -i ppp0 -p 51 -j ACCEPT
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 500 -j ACCEPT
# OPENVPN
iptables -A INPUT -i ppp0 -m state --state NEW -p udp --dport 5000 -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
iptables -A FORWARD -j MY_REJECT
# Routing
echo 1 > /proc/sys/net/ipv4/ip_forward 2> /dev/null
# 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
# Auskommentiert, da IPSEC mit RP_Filter nicht funktioniert!
# 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
echo "Deaktiviere IP-Routing"
echo 0 > /proc/sys/net/ipv4/ip_forward
# 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