Documentation Updates

git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@1918 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb
This commit is contained in:
teastep 2005-01-25 01:10:51 +00:00
parent 1142b86134
commit 6b86727898
2 changed files with 78 additions and 30 deletions

View File

@ -15,12 +15,12 @@
</author> </author>
</authorgroup> </authorgroup>
<pubdate>2004-07-11</pubdate> <pubdate>2005-01-23</pubdate>
<copyright> <copyright>
<year>2003</year> <year>2003</year>
<year>2004</year> <year>2005</year>
<holder>Thomas M. Eastep</holder> <holder>Thomas M. Eastep</holder>
</copyright> </copyright>
@ -31,18 +31,21 @@
1.2 or any later version published by the Free Software Foundation; with 1.2 or any later version published by the Free Software Foundation; with
no Invariant Sections, with no Front-Cover, and with no Back-Cover no Invariant Sections, with no Front-Cover, and with no Back-Cover
Texts. A copy of the license is included in the section entitled Texts. A copy of the license is included in the section entitled
<quote><ulink url="GnuCopyright.htm">GNU Free Documentation License</ulink></quote>.</para> <quote><ulink url="GnuCopyright.htm">GNU Free Documentation
License</ulink></quote>.</para>
</legalnotice> </legalnotice>
</articleinfo> </articleinfo>
<section> <section>
<title>Netfilter Overview</title> <title>Netfilter Overview</title>
<para>Netfilter consists of three tables: <emphasis role="bold">Filter</emphasis>, <para>Netfilter consists of three tables: <emphasis
<emphasis role="bold">Nat</emphasis> and <emphasis role="bold">Mangle</emphasis>. role="bold">Filter</emphasis>, <emphasis role="bold">Nat</emphasis> and
Each table has a number of build-in chains: <emphasis role="bold">PREROUTING</emphasis>, <emphasis role="bold">Mangle</emphasis>. Each table has a number of
<emphasis role="bold">INPUT</emphasis>, <emphasis role="bold">FORWARD</emphasis>, build-in chains: <emphasis role="bold">PREROUTING</emphasis>, <emphasis
<emphasis role="bold">OUTPUT</emphasis> and <emphasis role="bold">POSTROUTING</emphasis>.</para> role="bold">INPUT</emphasis>, <emphasis role="bold">FORWARD</emphasis>,
<emphasis role="bold">OUTPUT</emphasis> and <emphasis
role="bold">POSTROUTING</emphasis>.</para>
<para>Rules in the various tables are used as follows:</para> <para>Rules in the various tables are used as follows:</para>
@ -51,7 +54,8 @@
<term>Filter</term> <term>Filter</term>
<listitem> <listitem>
<para>Packet filtering (rejecting, dropping or accepting packets)</para> <para>Packet filtering (rejecting, dropping or accepting
packets)</para>
</listitem> </listitem>
</varlistentry> </varlistentry>
@ -69,7 +73,8 @@
<listitem> <listitem>
<para>General packet header modification such as setting the TOS <para>General packet header modification such as setting the TOS
value or marking packets for policy routing and traffic shaping.</para> value or marking packets for policy routing and traffic
shaping.</para>
</listitem> </listitem>
</varlistentry> </varlistentry>
</variablelist> </variablelist>
@ -78,34 +83,39 @@
chains within Netfilter. Note that not all table/chain combinations are chains within Netfilter. Note that not all table/chain combinations are
used.</para> used.</para>
<graphic fileref="images/Netfilter.png" /> <graphic align="center" fileref="images/Netfilter.png" />
<para><quote>Local Process</quote> means a process running on the <para><quote>Local Process</quote> means a process running on the
Shorewall system itself.</para> Shorewall system itself.</para>
<para>A more elaborate version of this flow is available <ulink <para>A more elaborate version of this flow is available <ulink
url="http://shorewall.net/pub/shorewall/misc/netfilterflow.pdf">here</ulink>.</para> url="http://shorewall.net/pub/shorewall/misc/netfilterflow.pdf">here</ulink>
and <ulink url="http://www.docum.org/docum.org/kptd/">this one</ulink>
contrasts the Netfilter flow with that of ipchains.</para>
<para>In the above diagram are boxes similar to this:</para> <para>In the above diagram are boxes similar to this:</para>
<graphic fileref="images/Legend.png" /> <graphic fileref="images/Legend.png" />
<para>The above box gives the name of the built-in chain (<emphasis <para>The above box gives the name of the built-in chain (<emphasis
role="bold">INPUT</emphasis>) along with the names of the tables (<emphasis role="bold">INPUT</emphasis>) along with the names of the tables
role="bold">Mangle</emphasis> and <emphasis role="bold">Filter</emphasis>) (<emphasis role="bold">Mangle</emphasis> and <emphasis
that the chain exists in and in the order that the chains are traversed. role="bold">Filter</emphasis>) that the chain exists in and in the order
The above sample indicates that packets go first through the <emphasis that the chains are traversed. The above sample indicates that packets go
role="bold">INPUT</emphasis> chain of the <emphasis role="bold">Mangle</emphasis> first through the <emphasis role="bold">INPUT</emphasis> chain of the
table then through the <emphasis role="bold">INPUT</emphasis> chain of the <emphasis role="bold">Mangle</emphasis> table then through the <emphasis
<emphasis role="bold">Filter</emphasis> table. When a chain is enclosed in role="bold">INPUT</emphasis> chain of the <emphasis
parentheses, Shorewall does not use the named chain (<emphasis role="bold">INPUT</emphasis>) role="bold">Filter</emphasis> table. When a chain is enclosed in
in that table (<emphasis role="bold">Mangle</emphasis>).</para> parentheses, Shorewall does not use the named chain (<emphasis
role="bold">INPUT</emphasis>) in that table (<emphasis
role="bold">Mangle</emphasis>).</para>
<important> <important>
<para>Keep in mind that chains in the <emphasis role="bold">Nat</emphasis> <para>Keep in mind that chains in the <emphasis
table are <emphasis role="bold">only traversed for new connection role="bold">Nat</emphasis> table are <emphasis role="bold">only
requests</emphasis> (including those related to existing connections) traversed for new connection requests</emphasis> (including those
while the chains in the other tables are traversed on every packet.</para> related to existing connections) while the chains in the other tables
are traversed on every packet.</para>
</important> </important>
<para>The above diagram should help you understand the output of <para>The above diagram should help you understand the output of
@ -137,7 +147,7 @@ Counters reset Sat Oct 11 08:12:57 PDT 2003</programlisting>
<programlisting> 785K 93M eth0_in all -- eth0 * 0.0.0.0/0 0.0.0.0/0 <programlisting> 785K 93M eth0_in all -- eth0 * 0.0.0.0/0 0.0.0.0/0
0 0 common all -- * * 0.0.0.0/0 0.0.0.0/0 0 0 common all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6 prefix `Shorewall:INPUT:REJECT:&#39; 0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6 prefix `Shorewall:INPUT:REJECT:'
0 0 reject all -- * * 0.0.0.0/0 0.0.0.0/0 0 0 reject all -- * * 0.0.0.0/0 0.0.0.0/0
Chain FORWARD (policy DROP 0 packets, 0 bytes) Chain FORWARD (policy DROP 0 packets, 0 bytes)
@ -146,7 +156,7 @@ Chain FORWARD (policy DROP 0 packets, 0 bytes)
0 0 DROP !icmp -- * * 0.0.0.0/0 0.0.0.0/0 state INVALID 0 0 DROP !icmp -- * * 0.0.0.0/0 0.0.0.0/0 state INVALID
0 0 eth0_fwd all -- eth0 * 0.0.0.0/0 0.0.0.0/0 0 0 eth0_fwd all -- eth0 * 0.0.0.0/0 0.0.0.0/0
0 0 common all -- * * 0.0.0.0/0 0.0.0.0/0 0 0 common all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6 prefix `Shorewall:FORWARD:REJECT:&#39; 0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6 prefix `Shorewall:FORWARD:REJECT:'
0 0 reject all -- * * 0.0.0.0/0 0.0.0.0/0 0 0 reject all -- * * 0.0.0.0/0 0.0.0.0/0
Chain OUTPUT (policy DROP 1 packets, 60 bytes) Chain OUTPUT (policy DROP 1 packets, 60 bytes)
@ -156,7 +166,7 @@ Chain OUTPUT (policy DROP 1 packets, 60 bytes)
0 0 DROP !icmp -- * * 0.0.0.0/0 0.0.0.0/0 state INVALID 0 0 DROP !icmp -- * * 0.0.0.0/0 0.0.0.0/0 state INVALID
922K 618M fw2net all -- * eth0 0.0.0.0/0 0.0.0.0/0 922K 618M fw2net all -- * eth0 0.0.0.0/0 0.0.0.0/0
0 0 common all -- * * 0.0.0.0/0 0.0.0.0/0 0 0 common all -- * * 0.0.0.0/0 0.0.0.0/0
0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6 prefix `Shorewall:OUTPUT:REJECT:&#39; 0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6 prefix `Shorewall:OUTPUT:REJECT:'
0 0 reject all -- * * 0.0.0.0/0 0.0.0.0/0</programlisting> 0 0 reject all -- * * 0.0.0.0/0 0.0.0.0/0</programlisting>
<para>Here is the eth0_in chain:</para> <para>Here is the eth0_in chain:</para>
@ -188,7 +198,8 @@ Chain net_dnat (1 references)
638 32968 REDIRECT tcp -- * * 0.0.0.0/0 !206.124.146.177 tcp dpt:80 redir ports 3128 638 32968 REDIRECT tcp -- * * 0.0.0.0/0 !206.124.146.177 tcp dpt:80 redir ports 3128
</programlisting> </programlisting>
<para>And finally, the <emphasis role="bold">Mangle</emphasis> table:</para> <para>And finally, the <emphasis role="bold">Mangle</emphasis>
table:</para>
<programlisting>Mangle Table <programlisting>Mangle Table

View File

@ -15,7 +15,7 @@
</author> </author>
</authorgroup> </authorgroup>
<pubdate>2005-01-01</pubdate> <pubdate>2005-01-14</pubdate>
<copyright> <copyright>
<year>2004</year> <year>2004</year>
@ -430,6 +430,43 @@ ifconfig most 192.168.1.31 netmask 255.255.255.0 up
/etc/rc.d/rc.bridge </programlisting> /etc/rc.d/rc.bridge </programlisting>
</blockquote> </blockquote>
<para>Joshua Schmidlkofer writes:</para>
<blockquote>
<programlisting>Bridge Setup for Gentoo
#install bridge-utils
emerge bridge-utils
## create a link for net.br0
cd /etc/init.d
ln -s net.eth0 net.br0
# Remove net.eth*, add net.br0 and bridge.
rc-update del net.eth0
rc-update del net.eth1
rc-update add net,br0 default
rc-update add bridge boot
/etc/conf.d/bridge:
#bridge contains the name of each bridge you want created.
bridge="br0"
# bridge_&lt;bridge&gt;_devices contains the devices to use at bridge startup.
bridge_br0_devices="eth0 eth1"
/etc/conf.d/net
iface_br0="10.0.0.1 broadcast 10.0.0.255 netmask 255.255.255.0"
#for dhcp:
#iface_br0="dhcp"
#comment this out if you use dhcp.
gateway="eth0/10.0.0.1" </programlisting>
</blockquote>
<para>Users who successfully configure bridges on other distributions, <para>Users who successfully configure bridges on other distributions,
with static or dynamic IP addresses, are encouraged to send <ulink with static or dynamic IP addresses, are encouraged to send <ulink
url="mailto:webmaster@shorewall.net">me</ulink> their configuration so I url="mailto:webmaster@shorewall.net">me</ulink> their configuration so I