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= nftables =
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nftables is meant to replace the [[iptables|iptables]] framework. nftables replaces the [[iptables|iptables]] framework.

<<TableOfContents>>
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nftables is under heavy development. Current version is v0.9. The Debian packages are up-to-date in unstable, also in stable (Stretch) the package is based on v0.7. Previous stable (Jessie) had it in backports.
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For a production firewall, you should keep using [[iptables]].

However, you would like to start testing nftables:

 * the new syntax and engine
 * get in touch with new workflows
 * report bug and request features

Currently, lots of bugs-fixes and features are added in each new release.
Starting with Debian Buster, nf_tables is the default backend when using iptables, by means of the iptables-nft layer (i.e, using iptables syntax with the nf_tables kernel subsystem).
This also affects ip6tables/arptables and ebtables.
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nftables requires a linux '''kernel >= 3.13''', but running a newer kernel is recommended. nftables requires a linux '''kernel >= 3.13''', but running a newer '''kernel >= 4.10''' is recommended.
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Also, nftables requires libnftnl, a public library which provides a low level interface to the kernel subsystem.

Aptitude will take care of all dependencies.
Not a requirement, but an advice: don't mix nftables and iptables rulesets unless you know what you are doing.
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=== What is nftables? === == What is nftables? ==
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=== Why a new framework? === == Should I build a firewall using a nftables? ==

Yes. Building new firewalls on top of iptables is discouraged.

== Should I replace an iptables firewall with a nftables one? ==

Yes, nftables is the replacement for iptables. There are some tools in place to ease in this task.

Please read: https://wiki.nftables.org/wiki-nftables/index.php/Moving_from_iptables_to_nftables

== Why a new framework? ==
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=== Should I stop working with iptables to build a firewall? ===
No. Currently, nftables is in an early development state. Nowadays, iptables is more stable.
== What are the major differences? ==
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=== Then, Why should I use nftables? ===
You can start testing what is meant to become the future of firewalls on Linux. Report bugs, request features and get in touch with the latest in this technology.

=== I knew the iptables syntax. Is there a new syntax is nftables? ===
Yes, but the nftables is better :-)

=== What are the major differences? ===
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nftables includes built-in data sets capabilities. In iptables this is not possible, and there is a separated tool: [[ipset|ipset]].

In the iptables framework there are tools per family: iptables, ip6tables, arptables, ebtables. Now, nftables allows you to manage all families in one single CLI tool.

This new framework features a new linux kernel subsystem, known as nf_tables.
The new engine mechanism is inspired by BPF-like systems, with a set of basic expressions, which can be combined to build complex filtering rules.

== I knew the iptables syntax. Is there a new syntax is nftables? ==

Yes, but the nftables one is better :-)

Help in migrating to nftables: https://wiki.nftables.org/wiki-nftables/index.php/Moving_from_iptables_to_nftables
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# nft add table filter # nft add table inet filter
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# nft add chain filter input { type filter hook input priority 0; } # nft add chain inet filter input { type filter hook input priority 0; }
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# nft add rule filter input counter accept # nft add rule inet filter input counter accept
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# nft list table filter # nft list table inet filter
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# nft flush chain filter input # nft flush chain inet filter input
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# nft delete chain filter input # nft delete chain inet filter input
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# nft delete table filter # nft delete table inet filter
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Debian ships an example configuration: Debian ships example configurations in:
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# nft -f /usr/share/doc/nftables/examples/basic.nft #/usr/share/doc/nftables/examples/
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# nft add rule filter input tcp dport 22 counter # nft add rule inet filter input tcp dport 22 counter
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Count and accept traffic in 80/tcp and 443/tcp in new an establised state: Count and accept traffic in 80/tcp and 443/tcp in new and establised state:
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# nft add rule filter input tcp dport {80, 443} ct state new,established counter accept
}}}

Export the ruleset in XML format (importing not yet supported):
{{{
nft export xml
# nft add rule inet filter input tcp dport {80, 443} ct state new,established counter accept

nftables is a framework by the Netfilter Project that provides packet filtering, network address translation (NAT) and other packet mangling.

Two of the most common uses of nftables is to provide firewall support and NAT.

nftables replaces the iptables framework.

Current status

Current version is v0.9. The Debian packages are up-to-date in unstable, also in stable (Stretch) the package is based on v0.7. Previous stable (Jessie) had it in backports.

Starting with Debian Buster, nf_tables is the default backend when using iptables, by means of the iptables-nft layer (i.e, using iptables syntax with the nf_tables kernel subsystem). This also affects ip6tables/arptables and ebtables.

Requirements

nftables requires a linux kernel >= 3.13, but running a newer kernel >= 4.10 is recommended.

Not a requirement, but an advice: don't mix nftables and iptables rulesets unless you know what you are doing.

FAQ

What is nftables?

Is the new framework by the Netfilter Project, allowing you to perform packet filtering (firewalling), NAT, mangling and packet classification.

Should I build a firewall using a nftables?

Yes. Building new firewalls on top of iptables is discouraged.

Should I replace an iptables firewall with a nftables one?

Yes, nftables is the replacement for iptables. There are some tools in place to ease in this task.

Please read: https://wiki.nftables.org/wiki-nftables/index.php/Moving_from_iptables_to_nftables

Why a new framework?

The previous framework (iptables) has several problems hard to address, regarding scalability, performance, code maintenance, etc..

What are the major differences?

In iptables there are several tables (filter, nat) and chains (FORWARD, INPUT...) by default. In nftables, there are no default tables/chains.

Also, in iptables you only have one target per rule (-j ACCEPT, -j LOG ...). In nftables, you can perform several actions in one single rule.

nftables includes built-in data sets capabilities. In iptables this is not possible, and there is a separated tool: ?ipset.

In the iptables framework there are tools per family: iptables, ip6tables, arptables, ebtables. Now, nftables allows you to manage all families in one single CLI tool.

This new framework features a new linux kernel subsystem, known as nf_tables. The new engine mechanism is inspired by BPF-like systems, with a set of basic expressions, which can be combined to build complex filtering rules.

I knew the iptables syntax. Is there a new syntax is nftables?

Yes, but the nftables one is better :-)

Help in migrating to nftables: https://wiki.nftables.org/wiki-nftables/index.php/Moving_from_iptables_to_nftables

new syntax

Create a basic IPv4 table:

# nft add table inet filter

Create a chain for input traffic IPv4:

# nft add chain inet filter input { type filter hook input priority 0; }

A rule to check that all is fine (IPv4):

# nft add rule inet filter input counter accept

Show all the previous:

# nft list table inet filter

Flush rules in chain filter/input:

# nft flush chain inet filter input

Delete the chain filter/input:

# nft delete chain inet filter input

Delete the table filter:

# nft delete table inet filter

The family parameter is optional. The default is 'ip':

# nft add table ip6 filter
# nft add chain ip6 filter input
# nft add rule ip6 filter input counter accept

Debian ships example configurations in:

#/usr/share/doc/nftables/examples/

Count traffic on destination port tcp/22:

# nft add rule inet filter input tcp dport 22 counter

Count and accept traffic in 80/tcp and 443/tcp in new and establised state:

# nft add rule inet filter input tcp dport {80, 443} ct state new,established counter accept

external resources

Check out the official nftables wiki: http://wiki.nftables.org/


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