How to Install nftables on Ubuntu 20.04 LTS

Nftables is a free & open source command line utility. It is easy to use and combines all tools of the IPtables framework such as iptables, ip6tables, arptables, etc. We can easily to create table,chain & add the rules with TCP port numbers. It helps to improved error reporting & reduction in code replication.

There are few steps to install & configure nftables on ubuntu:

Step 1: Update the System.

apt-get update

Step 2: Install the nftables on System.

apt install nftables

  • Install Iptables.

apt install iptables

Step 3: Start & Enable the nftables service.

systemctl start nftables.service
systemctl enable nftables.service

  • Check the nftables status.

systemctl status nftables.service

  • Here is the command output.

Step 4: Nftables Syntax & Examples.

nft [ -nNscaeSupyj ] [ -I directory ] [ -f filename | -i | cmd …]

  • To list all available options.

nft -h

  • Here is the command output.

  • Add a new table, with family “inet”.

nft add table inet table_name
nft add table inet filter
nft add table inet example_tables

  • To list all tables.

nft list tables

  • Here is the command output.

  • To add a new chain & accept all inbound traffic:

nft add chain inet example_tables example_chain '{ type filter hook input priority 0 ; policy accept ; }'

  • To list all chains.

nft list chains

  • Here is the command output.

  • To add a new rule & accept TCP port number.

nft add rule inet example_tables example_chain tcp dport 22 accept

  • To list ruleset.

nft list ruleset

  • Here is the command output.

  • To delete a rule:

nft delete rule inet table_name input handle 3
nft delete rule inet filter input handle 3

  • To save the ruleset.

nft list ruleset > /etc/nftables.conf

  • To save the rule in Iptables.

iptables-save > fwrules.txt

  • To display the save files.

cat /etc/nftables.conf
cat fwrules.txt

  • Here is the command output.

  • To run the following command for equivalent nft & nft ruleset dump.

iptables-restore-translate -f fwrules.txt
iptables-restore-translate -f fwrules.txt > ruleset.nft

  • Here is the command output.

  • An IP in nftables drop rule.

nft add rule ip filter output ip daddr ip-address drop
nft add rule ip filter output ip daddr 10.10.10.10 drop

  • In iptables, ip-address drop rule.

iptables -A OUTPUT -d 10.10.10.10 -j DROP

 

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