huschi.net

XTABLES-NFT(8)              System Manager's Manual             XTABLES-NFT(8)
NAME
       xtables-nft -- iptables using nftables kernel api
DESCRIPTION
       xtables-nft  are  versions of iptables that use the nftables API.  This
       is a set of tools to help the system administrator migrate the  ruleset
       from  iptables(8), ip6tables(8), arptables(8), and ebtables(8) to nfta-
       bles(8).
       The xtables-nft set is composed of several commands:
       o iptables-nft
       o iptables-nft-save
       o iptables-nft-restore
       o ip6tables-nft
       o ip6tables-nft-save
       o ip6tables-nft-restore
       o arptables-nft
       o ebtables-nft
         These tools use the libxtables framework extensions and hook  to  the
         nf_tables kernel subsystem using the nft_compat module.
USAGE
       The  xtables-nft  tools allow you to manage the nf_tables backend using
       the native syntax of iptables(8), ip6tables(8), arptables(8), and ebta-
       bles(8).
       You  should use the xtables-nft tools exactly the same way as you would
       use the corresponding original tools.
       Adding a rule will result in that rule being  added  to  the  nf_tables
       kernel  subsystem  instead.  Listing the ruleset will use the nf_tables
       backend as well.
       When these tools were designed, the  main  idea  was  to  replace  each
       legacy binary with a symlink to the xtables-nft program, for example:
            /sbin/iptables -> /usr/sbin/iptables-nft-multi
            /sbin/ip6tables -> /usr/sbin/ip6tables-nft-multi
            /sbin/arptables -> /usr/sbin/arptables-nft-multi
            /sbin/ebtables -> /usr/sbin/ebtables-nft-multi
       The  iptables  version  string  will  indicate  whether  the legacy API
       (get/setsockopt) or the new nf_tables api is used:
            iptables -V
            iptables v1.7 (nf_tables)
DIFFERENCES TO LEGACY IPTABLES
       Because the xtables-nft tools use the nf_tables kernel API, rule  addi-
       tions  and  deletions are always atomic.  Unlike iptables-legacy, ipta-
       bles-nft -A ..  will NOT need to retrieve the current ruleset from  the
       kernel, change it, and re-load the altered ruleset.  Instead, iptables-
       nft will tell the kernel to add one rule.  For this reason,  the  ipta-
       bles-legacy --wait option is a no-op in iptables-nft.
       Use of the xtables-nft tools allow monitoring ruleset changes using the
       xtables-monitor(8) command.
       When using -j TRACE to debug packet traversal to the ruleset, note that
       you will need to use xtables-monitor(8) in --trace mode to obtain moni-
       toring trace events.
EXAMPLES
       One basic example is creating the skeleton ruleset  in  nf_tables  from
       the xtables-nft tools, in a fresh machine:
            root@machine:~# iptables-nft -L
            [...]
            root@machine:~# ip6tables-nft -L
            [...]
            root@machine:~# arptables-nft -L
            [...]
            root@machine:~# ebtables-nft -L
            [...]
            root@machine:~# nft list ruleset
            table ip filter {
                 chain INPUT {
                      type filter hook input priority 0; policy accept;
                 }
                 chain FORWARD {
                      type filter hook forward priority 0; policy accept;
                 }
                 chain OUTPUT {
                      type filter hook output priority 0; policy accept;
                 }
            }
            table ip6 filter {
                 chain INPUT {
                      type filter hook input priority 0; policy accept;
                 }
                 chain FORWARD {
                      type filter hook forward priority 0; policy accept;
                 }
                 chain OUTPUT {
                      type filter hook output priority 0; policy accept;
                 }
            }
            table bridge filter {
                 chain INPUT {
                      type filter hook input priority -200; policy accept;
                 }
                 chain FORWARD {
                      type filter hook forward priority -200; policy accept;
                 }
                 chain OUTPUT {
                      type filter hook output priority -200; policy accept;
                 }
            }
            table arp filter {
                 chain INPUT {
                      type filter hook input priority 0; policy accept;
                 }
                 chain FORWARD {
                      type filter hook forward priority 0; policy accept;
                 }
                 chain OUTPUT {
                      type filter hook output priority 0; policy accept;
                 }
            }
       (please  note that in fresh machines, listing the ruleset for the first
       time results in all tables an chain being created).
       To migrate your complete filter ruleset, in the  case  of  iptables(8),
       you would use:
            root@machine:~# iptables-legacy-save > myruleset # reads from x_tables
            root@machine:~# iptables-nft-restore myruleset   # writes to nf_tables
       or
            root@machine:~# iptables-legacy-save | iptables-translate-restore | less
       to see how rules would look like in the nft nft(8) syntax.
LIMITATIONS
       You should use Linux kernel >= 4.17.
       The CLUSTERIP target is not supported.
       To   get   up-to-date   information   about   this,   please   head  to
       http://wiki.nftables.org/.
SEE ALSO
       nft(8), xtables-translate(8), xtables-monitor(8)
AUTHORS
       The  nftables  framework  is   written   by   the   Netfilter   project
       (https://www.netfilter.org).
       This   manual   page   was   written   by   Arturo   Borrero   Gonzalez
       <arturo AT debian.org> for the Debian project, but may be used by others.
       This documentation is free/libre under the terms of the GPLv2+.
                                   June 2018                    XTABLES-NFT(8)