Is it safe to open
Management interfaces give full control of the system. Make them reachable only from an admin network or VPN, change default credentials and keep the software patched.
How to open port 162
Open to everyone
# Linux iptables iptables -A INPUT -p udp --dport 162 -j ACCEPT # Ubuntu ufw ufw allow 162/udp # firewalld firewall-cmd --permanent --add-port=162/udp && firewall-cmd --reload # MikroTik /ip firewall filter add chain=input protocol=udp dst-port=162 action=accept place-before=0 comment="port 162" # Windows (PowerShell) New-NetFirewallRule -DisplayName "Port 162 UDP" -Direction Inbound -Protocol UDP -LocalPort 162 -Action Allow
Only for your addresses
# allow only one address or network (replace 203.0.113.0/24) iptables -A INPUT -p udp --dport 162 -s 203.0.113.0/24 -j ACCEPT iptables -A INPUT -p udp --dport 162 -j DROP ufw allow from 203.0.113.0/24 to any port 162 proto udp /ip firewall filter add chain=input protocol=udp dst-port=162 src-address=203.0.113.0/24 action=accept /ip firewall filter add chain=input protocol=udp dst-port=162 action=drop
If the server is behind a router, you also need a port forward (dst-nat). Behind ISP CGNAT (100.64.0.0/10 on the WAN) forwarding will not help: you need a public IP or a VPN.
What is listening
Check on the server
# what listens on the port ss -lntup | grep ':162 ' netstat -ano | findstr :162 # Windows lsof -i :162 # macOS