324 lines
4.5 KiB
HTML
324 lines
4.5 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Summary: (I like doing summaries first)</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="Masquerading Made Simple HOWTO"
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HREF="index.html"><LINK
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REL="PREVIOUS"
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TITLE="Introduction"
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HREF="intro.html"><LINK
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REL="NEXT"
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TITLE="Bitmore indepth version"
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HREF="indepth.html"></HEAD
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><BODY
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CLASS="SECT1"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Masquerading Made Simple HOWTO</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="intro.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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></TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="indepth.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="SECT1"
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><H1
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CLASS="SECT1"
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><A
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NAME="SUMMARY"
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></A
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>2. Summary: (I like doing summaries first)</H1
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><P
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> Assuming external internet card is eth0, and external IP is 123.12.23.43
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and the internal network card is eth1, then:
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</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="SCREEN"
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><TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>modprobe ipt_MASQUERADE</B
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> # If this fails, try continuing anyway
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -F; iptables -t nat -F; iptables -t mangle -F</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 123.12.23.43</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>echo 1 > /proc/sys/net/ipv4/ip_forward</B
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></PRE
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></FONT
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></TD
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></TR
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></TABLE
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><P
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> Or for a dial-up connection:
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</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="SCREEN"
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><TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>modprobe ipt_MASQUERADE</B
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> # If this fails, try continuing anyway
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -F; iptables -t nat -F; iptables -t mangle -F</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>echo 1 > /proc/sys/net/ipv4/ip_forward</B
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></PRE
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></FONT
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></TD
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></TR
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></TABLE
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><P
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> Then to secure it:
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</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="SCREEN"
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><TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -A INPUT -m state --state NEW -i ! eth0 -j ACCEPT</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -P INPUT DROP</B
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> #only if the first two are succesful
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -A FORWARD -i eth0 -o eth0 -j REJECT</B
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></PRE
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></FONT
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></TD
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></TR
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></TABLE
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><P
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> Or for a dial-up connection (with eth0 as the internal network card):
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</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="SCREEN"
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><TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -A INPUT -m state --state NEW -i ! ppp0 -j ACCEPT</B
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>
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -P INPUT DROP</B
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> #only if the first two are succesful
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<TT
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CLASS="PROMPT"
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>$></TT
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> <B
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CLASS="COMMAND"
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>iptables -A FORWARD -i ppp0 -o ppp0 -j REJECT</B
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></PRE
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></FONT
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></TD
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></TR
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></TABLE
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><P
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> And thats it! To view the rules do "<B
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CLASS="COMMAND"
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>iptables -t nat -L</B
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>"
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</P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
|
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
|
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ALIGN="left"
|
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VALIGN="top"
|
|
><A
|
|
HREF="intro.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
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WIDTH="34%"
|
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ALIGN="center"
|
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VALIGN="top"
|
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><A
|
|
HREF="index.html"
|
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ACCESSKEY="H"
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>Home</A
|
|
></TD
|
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><TD
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WIDTH="33%"
|
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ALIGN="right"
|
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VALIGN="top"
|
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><A
|
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HREF="indepth.html"
|
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ACCESSKEY="N"
|
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>Next</A
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></TD
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></TR
|
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><TR
|
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><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
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VALIGN="top"
|
|
>Introduction</TD
|
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><TD
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WIDTH="34%"
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|
ALIGN="center"
|
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VALIGN="top"
|
|
> </TD
|
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><TD
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WIDTH="33%"
|
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ALIGN="right"
|
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VALIGN="top"
|
|
>Bitmore indepth version</TD
|
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></TR
|
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></TABLE
|
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></DIV
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></BODY
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></HTML
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> |