updates for v3.0 .. take 1 ..

git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@2600 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb
This commit is contained in:
judas_iscariote 2005-08-31 06:42:41 +00:00
parent 98f1d5ed6a
commit 60bef971db
2 changed files with 27 additions and 284 deletions

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@ -13,7 +13,7 @@
</author>
</authorgroup>
<pubdate>2005-03-04</pubdate>
<pubdate>2005-08-31</pubdate>
<copyright>
<year>2001-2005</year>
@ -32,15 +32,6 @@
</legalnotice>
</articleinfo>
<note>
<para>Shorewall <quote>Ping</quote> management has evolved over time with
the latest change coming in Shorewall version 1.4.0. To find out which
version of Shorewall you are running, at a shell prompt type
<quote><command>/sbin/shorewall version</command></quote>. If that command
gives you an error, it's time to upgrade since you have a very old version
of Shorewall installed (1.2.4 or earlier).</para>
</note>
<note>
<para>Enabling <quote>ping</quote> will also enable ICMP-based
<emphasis>traceroute</emphasis>. For UDP-based traceroute, see the <ulink
@ -48,17 +39,17 @@
</note>
<section>
<title>Shorewall Versions &gt;= 2.0.0</title>
<title>'Ping' Management</title>
<para>In Shoreall 1.4.0 and later version, ICMP echo-request's are treated
just like any other connection request.</para>
<para>In Shorewall , ICMP echo-request's are treated just like any other
connection request.</para>
<para>In order to accept ping requests from zone z1 to zone z2 where the
policy for z1 to z2 is not ACCEPT, you need a rule in
<filename>/etc/shorewall/rules</filename> of the form:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
AllowPing z1 z2</programlisting>
Ping/ACCEPT z1 z2</programlisting>
<example>
<title>Ping from local zone to firewall</title>
@ -66,7 +57,7 @@ AllowPing z1 z2</programlisting>
<para>To permit ping from the local zone to the firewall:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
AllowPing loc fw</programlisting>
Ping/ACCEPT loc fw</programlisting>
</example>
<para>If you would like to accept <quote>ping</quote> by default even when
@ -76,13 +67,13 @@ AllowPing loc fw</programlisting>
<filename class="directory">/etc/shorewall</filename> and simply add this
line to the copy:</para>
<programlisting>AllowPing</programlisting>
<programlisting>Ping/ACCEPT</programlisting>
<para>With that rule in place, if you want to ignore <quote>ping</quote>
from z1 to z2 then you need a rule of the form:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
DropPing z1 z2</programlisting>
Ping/DROP z1 z2</programlisting>
<example>
<title>Silently drop pings from the Internet</title>
@ -91,7 +82,7 @@ DropPing z1 z2</programlisting>
<filename>/etc/shorewall/rules</filename>:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
DropPing net fw</programlisting>
Ping/DROP:none! net fw</programlisting>
</example>
<para>Note that the above rule may be used without changing the action
@ -99,244 +90,20 @@ DropPing net fw</programlisting>
remote pinging.</para>
</section>
<section>
<title>Shorewall Versions &gt;= 1.4.0</title>
<para>In Shoreall 1.4.0 and later version, ICMP echo-request's are treated
just like any other connection request.</para>
<para>In order to accept ping requests from zone z1 to zone z2 where the
policy for z1 to z2 is not ACCEPT, you need a rule in
<filename>/etc/shoreall/rules</filename> of the form:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
ACCEPT z1 z2 icmp 8</programlisting>
<example>
<title>Ping from local zone to firewall</title>
<para>To permit ping from the local zone to the firewall:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
ACCEPT loc fw icmp 8</programlisting>
</example>
<para>If you would like to accept <quote>ping</quote> by default even when
the relevant policy is DROP or REJECT, create /etc/shorewall/icmpdef if it
doesn't already exist and in that file place the following command:</para>
<programlisting>run_iptables -A icmpdef -p icmp --icmp-type 8 -j ACCEPT</programlisting>
<para>With that rule in place, if you want to ignore <quote>ping</quote>
from z1 to z2 then you need a rule of the form:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
DROP z1 z2 icmp 8</programlisting>
<example>
<title>Silently drop pings from the Internet</title>
<para>To drop ping from the internet, you would need this rule in
/etc/shorewall/rules:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
DROP net fw icmp 8</programlisting>
</example>
<para>Note that the above rule may be used without any additions to
/etc/shorewall/icmpdef to prevent your log from being flooded by messages
generated from remote pinging.</para>
</section>
<section>
<title>Shorewall Versions &gt;= 1.3.14 and &lt; 1.4.0 with
OLD_PING_HANDLING=No in /etc/shorewall/shorewall.conf</title>
<para>In 1.3.14, Ping handling was put under control of the rules and
policies just like any other connection request. In order to accept ping
requests from zone z1 to zone z2 where the policy for z1 to z2 is not
ACCEPT, you need a rule in /etc/shoreall/rules of the form:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
ACCEPT z1 z2 icmp 8</programlisting>
<example>
<title>Ping from local zone to firewall</title>
<para>To permit ping from the local zone to the firewall:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
ACCEPT loc fw icmp 8</programlisting>
</example>
<para>If you would like to accept <quote>ping</quote> by default even when
the relevant policy is DROP or REJECT, create /etc/shorewall/icmpdef if it
doesn't already exist and in that file place the following command:</para>
<programlisting>run_iptables -A icmpdef -p icmp --icmp-type 8 -j ACCEPT</programlisting>
<para>With that rule in place, if you want to ignore <quote>ping</quote>
from z1 to z2 then you need a rule of the form:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
DROP z1 z2 icmp 8</programlisting>
<example>
<title>Silently drop pings from the Internet</title>
<para>To drop ping from the internet, you would need this rule in
/etc/shorewall/rules:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
DROP net fw icmp 8</programlisting>
</example>
<para>The above rule may be used without any additions to
/etc/shorewall/icmpdef to prevent your log from being flooded by messages
generated from remote pinging.</para>
<note>
<para>There is one exception to the above description. In 1.3.14 and
1.3.14a, ping from the firewall itself is enabled unconditionally. This
suprising <quote>feature</quote> was removed in version 1.4.0.</para>
</note>
</section>
<section>
<title>Shorewall Versions &lt; 1.3.14 or with OLD_PING_HANDLING=Yes in
/etc/shorewall/shorewall.conf</title>
<para>There are several aspects to the old Shorewall Ping
management:</para>
<orderedlist>
<listitem>
<para>The <emphasis role="bold">noping</emphasis> and <emphasis
role="bold">filterping</emphasis> interface options in <ulink
url="Documentation.htm#Interfaces">/etc/shorewall/interfaces</ulink>.</para>
</listitem>
<listitem>
<para>The <emphasis role="bold">FORWARDPING</emphasis> option in
<ulink
url="Documentation.htm#Config">/etc/shorewall/shorewall.conf</ulink>.</para>
</listitem>
<listitem>
<para>Explicit rules in <ulink
url="Documentation.htm#rules">/etc/shorewall/rules</ulink>.</para>
</listitem>
</orderedlist>
<para>There are two cases to consider:</para>
<orderedlist>
<listitem>
<para>Ping requests addressed to the firewall itself; and</para>
</listitem>
<listitem>
<para>Ping requests being forwarded to another system. Included here
are all cases of packet forwarding including NAT, DNAT rule, Proxy ARP
and simple routing.</para>
</listitem>
</orderedlist>
<para>These cases will be covered separately.</para>
<section>
<title>Ping Requests Addressed to the Firewall Itself</title>
<para>For ping requests addressed to the firewall, the sequence is as
follows:</para>
<orderedlist>
<listitem>
<para>If neither <emphasis role="bold">noping</emphasis> nor
<emphasis role="bold">filterping</emphasis> are specified for the
interface that receives the ping request then the request will be
responded to with an ICMP echo-reply.</para>
</listitem>
<listitem>
<para>If <emphasis role="bold">noping</emphasis> is specified for
the interface that receives the ping request then the request is
ignored.</para>
</listitem>
<listitem>
<para>If <emphasis role="bold">filterping</emphasis> is specified
for the interface then the request is passed to the rules/policy
evaluation.</para>
</listitem>
</orderedlist>
</section>
<section>
<title>Ping Requests Forwarded by the Firewall</title>
<para>These requests are always passed to rules/policy
evaluation.</para>
<section>
<title>Rules Evaluation</title>
<para>Ping requests are ICMP type 8. So the general rule format
is:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
<emphasis>&lt;action&gt;</emphasis> <emphasis>&lt;source&gt;</emphasis> <emphasis>&lt;destination&gt;</emphasis> icmp 8</programlisting>
<example>
<title>Allow ping from DMZ to Net</title>
<para>Example 1. Accept pings from the dmz to the net:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
ACCEPT dmz net icmp 8</programlisting>
</example>
<example>
<title>Silently drop pings from the Net</title>
<para>Drop pings from the net to the firewall:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S)
DROP net fw icmp 8</programlisting>
</example>
</section>
<section>
<title>Policy Evaluation</title>
<para>If no applicable rule is found, then the policy for the source
to the destination is applied.</para>
<orderedlist>
<listitem>
<para>If the relevant policy is ACCEPT then the request is
responded to with an ICMP echo-reply.</para>
</listitem>
<listitem>
<para>If <emphasis role="bold">FORWARDPING</emphasis> is set to
Yes in /etc/shorewall/shorewall.conf then the request is responded
to with an ICMP echo-reply.</para>
</listitem>
<listitem>
<para>Otherwise, the relevant REJECT or DROP policy is used and
the request is either rejected or simply ignored.</para>
</listitem>
</orderedlist>
</section>
</section>
</section>
<appendix>
<title>Revision History</title>
<para><revhistory>
<revision>
<revnumber>1.3</revnumber>
<date>2005-08-31</date>
<authorinitials>CR</authorinitials>
<revremark>Updated for Shorewall 3</revremark>
</revision>
<revision>
<revnumber>1.2</revnumber>

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@ -15,12 +15,12 @@
</author>
</authorgroup>
<pubdate>2005-04-14</pubdate>
<pubdate>2005-08-31</pubdate>
<copyright>
<year>2002</year>
<year>2004</year>
<year>-</year>
<year>2005</year>
@ -41,41 +41,17 @@
<para>If you wish to run Samba on your firewall and access shares between
the firewall and local hosts, you need the following rules:</para>
<para><emphasis role="bold">/etc/shorewall/rules:</emphasis><programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S) SOURCE
# PORT(S)
ACCEPT fw loc udp 137:139
ACCEPT fw loc tcp 137,139,445
ACCEPT fw loc udp 1024: 137
ACCEPT loc fw udp 137:139
ACCEPT loc fw tcp 137,139,445
ACCEPT loc fw udp 1024: 137</programlisting></para>
<para>Users running Shorewall 2.0.0 or later may simpify the above through
use of the <firstterm>AllowSMB</firstterm> <ulink
url="Actions.html">action</ulink>:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S) SOURCE
# PORT(S)
AllowSMB fw loc
AllowSMB loc fw</programlisting>
SMB/ACCEPT fw loc
SMB/ACCEPT loc fw</programlisting>
<para>To pass traffic SMB/Samba traffic between zones Z1 and Z2:</para>
<para><emphasis role="bold">/etc/shorewall/rules:</emphasis><programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S) SOURCE
# PORT(S)
ACCEPT Z1 Z2 udp 137:139
ACCEPT Z1 Z2 tcp 137,139,445
ACCEPT Z1 Z2 udp 1024: 137
ACCEPT Z2 Z1 udp 137:139
ACCEPT Z2 Z1 tcp 137,139,445
ACCEPT Z1 Z1 udp 1024: 137</programlisting></para>
<para>Again, users running 2.0.0 or later may write:</para>
<programlisting>#ACTION SOURCE DEST PROTO DEST PORT(S) SOURCE
# PORT(S)
AllowSMB Z1 Z2
AllowSMB Z2 Z1</programlisting>
SMB/ACCEPT Z1 Z2
SMB/ACCEPT Z2 Z1</programlisting>
<para>To make network browsing (<quote>Network Neighborhood</quote>) work
properly between Z1 and Z2 requires a Windows Domain Controller and/or a
@ -95,8 +71,8 @@ AllowSMB Z2 Z1</programlisting>
<listitem>
<para>Edit the copies and remove the <emphasis
role="bold">DropSMB</emphasis> and <emphasis
role="bold">RejectSMB</emphasis> lines.</para>
role="bold">SMB/DROP</emphasis> and <emphasis
role="bold">SMB/REJECT</emphasis> lines.</para>
</listitem>
<listitem>