Enable Masquerade to allow port forwarding
sudo vi /etc/ufw/before.rules
For SNMP Trap forwarding, add the following lines at the top before the *filter section
*nat
:PREROUTING ACCEPT [0:0]
-A PREROUTING -p udp --dport 162 -j REDIRECT --to-port 10162
COMMIT
Apply the firewall changes
sudo ufw allow in 162/udp
sudo ufw allow in 10162/udp
sudo ufw reload