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Add an IP address to an nftables blocklist

caution rootFirewalldebian, ubuntu

Caution: This command changes the system. Understand what it does before you run it.

Adjust the values, the command updates live
root@server
nft add element inet filter blocklist '{ 203.0.113.25 }'

Adds the address to the previously created blocklist set, and the associated drop rule takes effect immediately. Multiple entries can be specified inside the curly braces, separated by commas. nft list set inet filter blocklist shows the contents, and an entry is removed with nft delete element using the same syntax.

Note: The set only accepts IPv4. IPv6 needs a second set with type ipv6_addr and a rule with ip6 saddr.

Also searched as

  • nftables block ip address
  • nft add element to set
  • add ip to nftables blocklist

Related one-liners

All in Firewall

Create an IP blocklist set in nftables

#nft add set inet filter blocklist '{ type ipv4_addr; flags interval; }' && nft insert rule inet filter input ip saddr @blocklist drop
cautionFirewall

Open a port with nftables

#nft insert rule inet filter input tcp dport 443 accept
cautionFirewall

Show the complete nftables ruleset with handles

#nft -a list ruleset
harmlessFirewall

Ban an IP address manually in CrowdSec

#cscli decisions add --ip 203.0.113.25 --duration 24h --reason 'manual ban'
cautionFirewall

Block an IP address or subnet with ufw

#ufw insert 1 deny from 203.0.113.0/24
cautionFirewall

Show active CrowdSec decisions and bans

#cscli decisions list
harmlessFirewall

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