422 lines
18 KiB
Groff
Executable File
422 lines
18 KiB
Groff
Executable File
.TH IP6TABLES 8 "" "iptables 1.4.4" "iptables 1.4.4"
|
|
.\"
|
|
.\" Man page written by Andras Kis-Szabo <kisza@sch.bme.hu>
|
|
.\" It is based on iptables man page.
|
|
.\"
|
|
.\" iptables page by Herve Eychenne <rv@wallfire.org>
|
|
.\" It is based on ipchains man page.
|
|
.\"
|
|
.\" ipchains page by Paul ``Rusty'' Russell March 1997
|
|
.\" Based on the original ipfwadm man page by Jos Vos <jos@xos.nl>
|
|
.\"
|
|
.\" This program is free software; you can redistribute it and/or modify
|
|
.\" it under the terms of the GNU General Public License as published by
|
|
.\" the Free Software Foundation; either version 2 of the License, or
|
|
.\" (at your option) any later version.
|
|
.\"
|
|
.\" This program is distributed in the hope that it will be useful,
|
|
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
.\" GNU General Public License for more details.
|
|
.\"
|
|
.\" You should have received a copy of the GNU General Public License
|
|
.\" along with this program; if not, write to the Free Software
|
|
.\" Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
.\"
|
|
.\"
|
|
.SH NAME
|
|
ip6tables \(em IPv6 packet filter administration
|
|
.SH SYNOPSIS
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] {\fB\-A\fP|\fB\-D\fP} \fIchain
|
|
rule-specification\fP [\fIoptions...\fP]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-I\fP \fIchain\fP [\fIrulenum\fP]
|
|
\fIrule-specification\fP [\fIoptions...\fP]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-R\fP \fIchain rulenum
|
|
rule-specification\fP [\fIoptions...\fP]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-D\fP \fIchain rulenum\fP
|
|
[\fIoptions...\fP]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-S\fP [\fIchain\fP [\fIrulenum\fP]]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] {\fB\-F\fP|\fB\-L\fP|\fB\-Z\fP}
|
|
[\fIchain\fP [\fIrulenum\fP]] [\fIoptions...\fP]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-N\fP \fIchain\fP
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-X\fP [\fIchain\fP]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-P\fP \fIchain target\fP
|
|
[\fIoptions...\fP]
|
|
.PP
|
|
\fBip6tables\fP [\fB\-t\fP \fItable\fP] \fB\-E\fP \fIold-chain-name new-chain-name\fP
|
|
.SH DESCRIPTION
|
|
\fBIp6tables\fP is used to set up, maintain, and inspect the
|
|
tables of IPv6 packet
|
|
filter rules in the Linux kernel. Several different tables
|
|
may be defined. Each table contains a number of built-in
|
|
chains and may also contain user-defined chains.
|
|
.PP
|
|
Each chain is a list of rules which can match a set of packets. Each
|
|
rule specifies what to do with a packet that matches. This is called
|
|
a `target', which may be a jump to a user-defined chain in the same
|
|
table.
|
|
.SH TARGETS
|
|
A firewall rule specifies criteria for a packet and a target. If the
|
|
packet does not match, the next rule in the chain is the examined; if
|
|
it does match, then the next rule is specified by the value of the
|
|
target, which can be the name of a user-defined chain or one of the
|
|
special values \fBACCEPT\fP, \fBDROP\fP, \fBQUEUE\fP or \fBRETURN\fP.
|
|
.PP
|
|
\fBACCEPT\fP means to let the packet through.
|
|
\fBDROP\fP means to drop the packet on the floor.
|
|
\fBQUEUE\fP means to pass the packet to userspace.
|
|
(How the packet can be received
|
|
by a userspace process differs by the particular queue handler. 2.4.x
|
|
and 2.6.x kernels up to 2.6.13 include the \fBip_queue\fP
|
|
queue handler. Kernels 2.6.14 and later additionally include the
|
|
\fBnfnetlink_queue\fP queue handler. Packets with a target of QUEUE will be
|
|
sent to queue number '0' in this case. Please also see the \fBNFQUEUE\fP
|
|
target as described later in this man page.)
|
|
\fBRETURN\fP means stop traversing this chain and resume at the next
|
|
rule in the
|
|
previous (calling) chain. If the end of a built-in chain is reached
|
|
or a rule in a built-in chain with target \fBRETURN\fP
|
|
is matched, the target specified by the chain policy determines the
|
|
fate of the packet.
|
|
.SH TABLES
|
|
There are currently three independent tables (which tables are present
|
|
at any time depends on the kernel configuration options and which
|
|
modules are present).
|
|
.TP
|
|
\fB\-t\fP, \fB\-\-table\fP \fItable\fP
|
|
This option specifies the packet matching table which the command
|
|
should operate on. If the kernel is configured with automatic module
|
|
loading, an attempt will be made to load the appropriate module for
|
|
that table if it is not already there.
|
|
|
|
The tables are as follows:
|
|
.RS
|
|
.TP .4i
|
|
\fBfilter\fP:
|
|
This is the default table (if no \-t option is passed). It contains
|
|
the built-in chains \fBINPUT\fP (for packets destined to local sockets),
|
|
\fBFORWARD\fP (for packets being routed through the box), and
|
|
\fBOUTPUT\fP (for locally-generated packets).
|
|
.TP
|
|
\fBmangle\fP:
|
|
This table is used for specialized packet alteration. Until kernel
|
|
2.4.17 it had two built-in chains: \fBPREROUTING\fP
|
|
(for altering incoming packets before routing) and \fBOUTPUT\fP
|
|
(for altering locally-generated packets before routing).
|
|
Since kernel 2.4.18, three other built-in chains are also supported:
|
|
\fBINPUT\fP (for packets coming into the box itself), \fBFORWARD\fP
|
|
(for altering packets being routed through the box), and \fBPOSTROUTING\fP
|
|
(for altering packets as they are about to go out).
|
|
.TP
|
|
\fBraw\fP:
|
|
This table is used mainly for configuring exemptions from connection
|
|
tracking in combination with the NOTRACK target. It registers at the netfilter
|
|
hooks with higher priority and is thus called before ip_conntrack, or any other
|
|
IP tables. It provides the following built-in chains: \fBPREROUTING\fP
|
|
(for packets arriving via any network interface) \fBOUTPUT\fP
|
|
(for packets generated by local processes)
|
|
.RE
|
|
.SH OPTIONS
|
|
The options that are recognized by
|
|
\fBip6tables\fP can be divided into several different groups.
|
|
.SS COMMANDS
|
|
These options specify the specific action to perform. Only one of them
|
|
can be specified on the command line unless otherwise specified
|
|
below. For all the long versions of the command and option names, you
|
|
need to use only enough letters to ensure that
|
|
\fBip6tables\fP can differentiate it from all other options.
|
|
.TP
|
|
\fB\-A\fP, \fB\-\-append\fP \fIchain rule-specification\fP
|
|
Append one or more rules to the end of the selected chain.
|
|
When the source and/or destination names resolve to more than one
|
|
address, a rule will be added for each possible address combination.
|
|
.TP
|
|
\fB\-D\fP, \fB\-\-delete\fP \fIchain rule-specification\fP
|
|
.ns
|
|
.TP
|
|
\fB\-D\fP, \fB\-\-delete\fP \fIchain rulenum\fP
|
|
Delete one or more rules from the selected chain. There are two
|
|
versions of this command: the rule can be specified as a number in the
|
|
chain (starting at 1 for the first rule) or a rule to match.
|
|
.TP
|
|
\fB\-I\fP, \fB\-\-insert\fP \fIchain\fP [\fIrulenum\fP] \fIrule-specification\fP
|
|
Insert one or more rules in the selected chain as the given rule
|
|
number. So, if the rule number is 1, the rule or rules are inserted
|
|
at the head of the chain. This is also the default if no rule number
|
|
is specified.
|
|
.TP
|
|
\fB\-R\fP, \fB\-\-replace\fP \fIchain rulenum rule-specification\fP
|
|
Replace a rule in the selected chain. If the source and/or
|
|
destination names resolve to multiple addresses, the command will
|
|
fail. Rules are numbered starting at 1.
|
|
.TP
|
|
\fB\-L\fP, \fB\-\-list\fP [\fIchain\fP]
|
|
List all rules in the selected chain. If no chain is selected, all
|
|
chains are listed. Like every other ip6tables command, it applies to the
|
|
specified table (filter is the default).
|
|
.IP ""
|
|
Please note that it is often used with the \fB\-n\fP
|
|
option, in order to avoid long reverse DNS lookups.
|
|
It is legal to specify the \fB\-Z\fP
|
|
(zero) option as well, in which case the chain(s) will be atomically
|
|
listed and zeroed. The exact output is affected by the other
|
|
arguments given. The exact rules are suppressed until you use
|
|
.nf
|
|
ip6tables \-L \-v
|
|
.fi
|
|
.TP
|
|
\fB\-S\fP, \fB\-\-list\-rules\fP [\fIchain\fP]
|
|
Print all rules in the selected chain. If no chain is selected, all
|
|
chains are printed like ip6tables-save. Like every other ip6tables command,
|
|
it applies to the specified table (filter is the default).
|
|
.TP
|
|
\fB\-F\fP, \fB\-\-flush\fP [\fIchain\fP]
|
|
Flush the selected chain (all the chains in the table if none is given).
|
|
This is equivalent to deleting all the rules one by one.
|
|
.TP
|
|
\fB\-Z\fP, \fB\-\-zero\fP [\fIchain\fP [\fIrulenum\fP]]
|
|
Zero the packet and byte counters in all chains, or only the given chain,
|
|
or only the given rule in a chain. It is legal to
|
|
specify the
|
|
\fB\-L\fP, \fB\-\-list\fP
|
|
(list) option as well, to see the counters immediately before they are
|
|
cleared. (See above.)
|
|
.TP
|
|
\fB\-N\fP, \fB\-\-new\-chain\fP \fIchain\fP
|
|
Create a new user-defined chain by the given name. There must be no
|
|
target of that name already.
|
|
.TP
|
|
\fB\-X\fP, \fB\-\-delete\-chain\fP [\fIchain\fP]
|
|
Delete the optional user-defined chain specified. There must be no references
|
|
to the chain. If there are, you must delete or replace the referring rules
|
|
before the chain can be deleted. The chain must be empty, i.e. not contain
|
|
any rules. If no argument is given, it will attempt to delete every
|
|
non-builtin chain in the table.
|
|
.TP
|
|
\fB\-P\fP, \fB\-\-policy\fP \fIchain target\fP
|
|
Set the policy for the chain to the given target. See the section \fBTARGETS\fP
|
|
for the legal targets. Only built-in (non-user-defined) chains can have
|
|
policies, and neither built-in nor user-defined chains can be policy
|
|
targets.
|
|
.TP
|
|
\fB\-E\fP, \fB\-\-rename\-chain\fP \fIold\-chain new\-chain\fP
|
|
Rename the user specified chain to the user supplied name. This is
|
|
cosmetic, and has no effect on the structure of the table.
|
|
.TP
|
|
\fB\-A\fP, \fB\-\-append\fP \fIchain rule-specification\fP
|
|
Append one or more rules to the end of the selected chain.
|
|
When the source and/or destination names resolve to more than one
|
|
address, a rule will be added for each possible address combination.
|
|
.TP
|
|
\fB\-h\fP
|
|
Help.
|
|
Give a (currently very brief) description of the command syntax.
|
|
.SS PARAMETERS
|
|
The following parameters make up a rule specification (as used in the
|
|
add, delete, insert, replace and append commands).
|
|
.TP
|
|
[\fB!\fP] \fB\-p\fP, \fB\-\-protocol\fP \fIprotocol\fP
|
|
The protocol of the rule or of the packet to check.
|
|
The specified protocol can be one of \fBtcp\fP, \fBudp\fP, \fBudplite\fP,
|
|
\fBicmpv6\fP, \fBesp\fP, \fBmh\fP or \fBall\fP,
|
|
or it can be a numeric value, representing one of these protocols or a
|
|
different one. A protocol name from /etc/protocols is also allowed.
|
|
But IPv6 extension headers except \fBesp\fP are not allowed.
|
|
\fBesp\fP and \fBipv6\-nonext\fP
|
|
can be used with Kernel version 2.6.11 or later.
|
|
A "!" argument before the protocol inverts the
|
|
test. The number zero is equivalent to \fBall\fP.
|
|
Protocol \fBall\fP
|
|
will match with all protocols and is taken as default when this
|
|
option is omitted.
|
|
.TP
|
|
[\fB!\fP] \fB\-s\fP, \fB\-\-source\fP \fIaddress\fP[\fB/\fP\fImask\fP]
|
|
Source specification.
|
|
\fIAddress\fP can be either be a hostname,
|
|
a network IP address (with \fB/\fP\fImask\fP), or a plain IP address.
|
|
Names will be resolved once only, before the rule is submitted to the kernel.
|
|
Please note that specifying any name to be resolved with a remote query such as
|
|
DNS is a really bad idea.
|
|
(Resolving network names is not supported at this time.)
|
|
The \fImask\fP is a plain number,
|
|
specifying the number of 1's at the left side of the network mask.
|
|
A "!" argument before the address specification inverts the sense of
|
|
the address. The flag \fB\-\-src\fP
|
|
is an alias for this option.
|
|
Multiple addresses can be specified, but this will \fBexpand to multiple
|
|
rules\fP (when adding with \-A), or will cause multiple rules to be
|
|
deleted (with \-D).
|
|
.TP
|
|
[\fB!\fP] \fB\-d\fP, \fB\-\-destination\fP \fIaddress\fP[\fB/\fP\fImask\fP]
|
|
Destination specification.
|
|
See the description of the \fB\-s\fP
|
|
(source) flag for a detailed description of the syntax. The flag
|
|
\fB\-\-dst\fP is an alias for this option.
|
|
.TP
|
|
\fB\-j\fP, \fB\-\-jump\fP \fItarget\fP
|
|
This specifies the target of the rule; i.e., what to do if the packet
|
|
matches it. The target can be a user-defined chain (other than the
|
|
one this rule is in), one of the special builtin targets which decide
|
|
the fate of the packet immediately, or an extension (see \fBEXTENSIONS\fP
|
|
below). If this
|
|
option is omitted in a rule (and \fB\-g\fP
|
|
is not used), then matching the rule will have no
|
|
effect on the packet's fate, but the counters on the rule will be
|
|
incremented.
|
|
.TP
|
|
\fB\-g\fP, \fB\-\-goto\fP \fIchain\fP
|
|
This specifies that the processing should continue in a user
|
|
specified chain. Unlike the \-\-jump option return will not continue
|
|
processing in this chain but instead in the chain that called us via
|
|
\-\-jump.
|
|
.TP
|
|
[\fB!\fP] \fB\-i\fP, \fB\-\-in\-interface\fP \fIname\fP
|
|
Name of an interface via which a packet was received (only for
|
|
packets entering the \fBINPUT\fP, \fBFORWARD\fP and \fBPREROUTING\fP
|
|
chains). When the "!" argument is used before the interface name, the
|
|
sense is inverted. If the interface name ends in a "+", then any
|
|
interface which begins with this name will match. If this option is
|
|
omitted, any interface name will match.
|
|
.TP
|
|
[\fB!\fP] \fB\-o\fP, \fB\-\-out\-interface\fP \fIname\fP
|
|
Name of an interface via which a packet is going to be sent (for packets
|
|
entering the \fBFORWARD\fP, \fBOUTPUT\fP and \fBPOSTROUTING\fP
|
|
chains). When the "!" argument is used before the interface name, the
|
|
sense is inverted. If the interface name ends in a "+", then any
|
|
interface which begins with this name will match. If this option is
|
|
omitted, any interface name will match.
|
|
.\" Currently not supported (header-based)
|
|
.\" .TP
|
|
.\" [\fB!\fP] \fB\-f\fP, \fB\-\-fragment\fP
|
|
.\" This means that the rule only refers to second and further fragments
|
|
.\" of fragmented packets. Since there is no way to tell the source or
|
|
.\" destination ports of such a packet (or ICMP type), such a packet will
|
|
.\" not match any rules which specify them. When the "!" argument
|
|
.\" precedes the "\-f" flag, the rule will only match head fragments, or
|
|
.\" unfragmented packets.
|
|
.TP
|
|
\fB\-c\fP, \fB\-\-set\-counters\fP \fIpackets bytes\fP
|
|
This enables the administrator to initialize the packet and byte
|
|
counters of a rule (during \fBINSERT\fP, \fBAPPEND\fP, \fBREPLACE\fP
|
|
operations).
|
|
.SS "OTHER OPTIONS"
|
|
The following additional options can be specified:
|
|
.TP
|
|
\fB\-v\fP, \fB\-\-verbose\fP
|
|
Verbose output. This option makes the list command show the interface
|
|
name, the rule options (if any), and the TOS masks. The packet and
|
|
byte counters are also listed, with the suffix 'K', 'M' or 'G' for
|
|
1000, 1,000,000 and 1,000,000,000 multipliers respectively (but see
|
|
the \fB\-x\fP flag to change this).
|
|
For appending, insertion, deletion and replacement, this causes
|
|
detailed information on the rule or rules to be printed.
|
|
.TP
|
|
\fB\-n\fP, \fB\-\-numeric\fP
|
|
Numeric output.
|
|
IP addresses and port numbers will be printed in numeric format.
|
|
By default, the program will try to display them as host names,
|
|
network names, or services (whenever applicable).
|
|
.TP
|
|
\fB\-x\fP, \fB\-\-exact\fP
|
|
Expand numbers.
|
|
Display the exact value of the packet and byte counters,
|
|
instead of only the rounded number in K's (multiples of 1000)
|
|
M's (multiples of 1000K) or G's (multiples of 1000M). This option is
|
|
only relevant for the \fB\-L\fP command.
|
|
.TP
|
|
\fB\-\-line\-numbers\fP
|
|
When listing rules, add line numbers to the beginning of each rule,
|
|
corresponding to that rule's position in the chain.
|
|
.TP
|
|
\fB\-\-modprobe=\fP\fIcommand\fP
|
|
When adding or inserting rules into a chain, use \fIcommand\fP
|
|
to load any necessary modules (targets, match extensions, etc).
|
|
.SH MATCH EXTENSIONS
|
|
ip6tables can use extended packet matching modules. These are loaded
|
|
in two ways: implicitly, when \fB\-p\fP or \fB\-\-protocol\fP
|
|
is specified, or with the \fB\-m\fP or \fB\-\-match\fP
|
|
options, followed by the matching module name; after these, various
|
|
extra command line options become available, depending on the specific
|
|
module. You can specify multiple extended match modules in one line,
|
|
and you can use the \fB\-h\fP or \fB\-\-help\fP
|
|
options after the module has been specified to receive help specific
|
|
to that module.
|
|
.PP
|
|
The following are included in the base package, and most of these can
|
|
be preceded by a "\fB!\fP" to invert the sense of the match.
|
|
.\" @MATCH@
|
|
.SH TARGET EXTENSIONS
|
|
ip6tables can use extended target modules: the following are included
|
|
in the standard distribution.
|
|
.\" @TARGET@
|
|
.SH DIAGNOSTICS
|
|
Various error messages are printed to standard error. The exit code
|
|
is 0 for correct functioning. Errors which appear to be caused by
|
|
invalid or abused command line parameters cause an exit code of 2, and
|
|
other errors cause an exit code of 1.
|
|
.SH BUGS
|
|
Bugs? What's this? ;-)
|
|
Well... the counters are not reliable on sparc64.
|
|
.SH COMPATIBILITY WITH IPCHAINS
|
|
This \fBip6tables\fP
|
|
is very similar to ipchains by Rusty Russell. The main difference is
|
|
that the chains \fBINPUT\fP and \fBOUTPUT\fP
|
|
are only traversed for packets coming into the local host and
|
|
originating from the local host respectively. Hence every packet only
|
|
passes through one of the three chains (except loopback traffic, which
|
|
involves both INPUT and OUTPUT chains); previously a forwarded packet
|
|
would pass through all three.
|
|
.PP
|
|
The other main difference is that \fB\-i\fP refers to the input interface;
|
|
\fB\-o\fP refers to the output interface, and both are available for packets
|
|
entering the \fBFORWARD\fP chain.
|
|
There are several other changes in ip6tables.
|
|
.SH SEE ALSO
|
|
\fBip6tables\-save\fP(8),
|
|
\fBip6tables\-restore\fP(8),
|
|
\fBiptables\fP(8),
|
|
\fBiptables\-save\fP(8),
|
|
\fBiptables\-restore\fP(8),
|
|
\fBlibipq\fP(3).
|
|
.PP
|
|
The packet-filtering-HOWTO details iptables usage for
|
|
packet filtering,
|
|
the netfilter-extensions-HOWTO details the extensions that are
|
|
not in the standard distribution,
|
|
and the netfilter-hacking-HOWTO details the netfilter internals.
|
|
.br
|
|
See
|
|
.BR "http://www.netfilter.org/" .
|
|
.SH AUTHORS
|
|
Rusty Russell wrote iptables, in early consultation with Michael
|
|
Neuling.
|
|
.PP
|
|
Marc Boucher made Rusty abandon ipnatctl by lobbying for a generic packet
|
|
selection framework in iptables, then wrote the mangle table, the owner match,
|
|
the mark stuff, and ran around doing cool stuff everywhere.
|
|
.PP
|
|
James Morris wrote the TOS target, and tos match.
|
|
.PP
|
|
Jozsef Kadlecsik wrote the REJECT target.
|
|
.PP
|
|
Harald Welte wrote the ULOG and NFQUEUE target, the new libiptc, as well as TTL match+target and libipulog.
|
|
.PP
|
|
The Netfilter Core Team is: Marc Boucher, Martin Josefsson, Yasuyuki Kozakai,
|
|
Jozsef Kadlecsik, Patrick McHardy, James Morris, Pablo Neira Ayuso,
|
|
Harald Welte and Rusty Russell.
|
|
.PP
|
|
ip6tables man page created by Andras Kis-Szabo, based on
|
|
iptables man page written by Herve Eychenne <rv@wallfire.org>.
|
|
.\" .. and did I mention that we are incredibly cool people?
|
|
.\" .. sexy, too ..
|
|
.\" .. witty, charming, powerful ..
|
|
.\" .. and most of all, modest ..
|