Port 162 (SNMP trap)

Devices send SNMP traps (unsolicited alerts) to a manager listening on UDP 162.

Well-known (system) port, 0-1023 UDP Monitoring and logging Do not expose to the internet

Port 162 is normally used over UDP; the checker tests TCP only, so a "filtered" result does not mean the UDP service is down.

What port 162 is used for

Devices send SNMP traps (unsolicited alerts) to a manager listening on UDP 162.

Do not expose to the internet. Only your devices need to reach it; accept traps from known sources only.

Service nameProtoDescriptionAssigneeReference

snmptrap TCP SNMPTRAP Marshall Rose -

snmptrap UDP SNMPTRAP Marshall Rose -

Linux: UDP 162

sudo ss -ulnp 'sport = :162'

Linux / macOS: which process owns the port

sudo lsof -nP -i :162

Windows (Command Prompt)

netstat -ano | findstr :162

Windows (PowerShell)

Get-NetUDPEndpoint -LocalPort 162

UDP probe (no reply does not prove it is closed)

nc -vzu -w 5 HOST 162

ufw

sudo ufw deny 162/udp

iptables

sudo iptables -A INPUT -p udp --dport 162 -j DROP

nftables

sudo nft add rule inet filter input udp dport 162 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block UDP 162' -Direction Inbound -Protocol UDP -LocalPort 162 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.