Block all inbound traffic from a source IP.

Section: Firewalling with nftables and iptables

Drop traffic from IP

bash
bash
sudo iptables -A INPUT -s 203.0.113.25 -j DROP
Explanation

Block all inbound traffic from a source IP.

Learn the surrounding workflow

Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.

Related commands

Same sheet · prioritizing Firewalling with nftables and iptables
List iptables rules
Show IPv4 filter rules with counters.
OpenIn sheetbashsame section
Export iptables rules
Dump current iptables rules in restore format.
OpenIn sheetbashsame section
Allow SSH with iptables
Insert a rule allowing inbound SSH.
OpenIn sheetbashsame section
Enable masquerading
Apply source NAT for outbound traffic.
OpenIn sheetbashsame section
Show nftables rules
Display the active nftables ruleset.
OpenIn sheetbashsame section
Create nftables table
Create an inet filter table.
OpenIn sheetbashsame section