Inbound Traffic Blocked, Check Firewall Settings May 2026

sudo iptables -L -n -v Look for a default policy of DROP or REJECT on the INPUT chain. Example blocking line:

sudo firewall-cmd --list-all Check the services and ports sections. If your port is missing, inbound traffic is blocked.

Issue: Users or services cannot connect to your server, application, or device from an external network (e.g., the internet or another subnet). Connection attempts time out or are actively rejected. inbound traffic blocked, check firewall settings

# Linux / macOS sudo netstat -tulpn | grep LISTEN # or ss -tuln netstat -an | findstr "LISTENING"

sudo pfctl -s rules Disable temporarily: sudo iptables -L -n -v Look for a

Get-NetFirewallRule | Where-Object $_.Direction -eq 'Inbound' -and $_.Enabled -eq 'True' | Format-Table DisplayName, Action Use with caution; only for testing.

# Test TCP port nc -zv <target-ip> <port> telnet <target-ip> <port> Test with curl (HTTP) curl -v http://<target-ip>:<port> Issue: Users or services cannot connect to your

Chain INPUT (policy DROP)