Iptables

Listing all rules

sudo iptables -S

To allow SNMP ports, login as root and execute this command on your terminal:

iptables -I INPUT -p udp -m udp --dport 161 -j ACCEPT
iptables -I INPUT -p udp -m udp --dport 162 -j ACCEPT
iptables-save > /etc/sysconfig/iptables