dmarescajr@dmarescajr-desktop:~$ sudo iptables -F
dmarescajr@dmarescajr-desktop:~$ sudo iptables -A INPUT -p tcp --source 192.168.1.101 --dport 613 -j ACCEPT 
dmarescajr@dmarescajr-desktop:~$ sudo iptables -A INPUT -p tcp --source 192.168.1.102 --dport 613 -j ACCEPT 
dmarescajr@dmarescajr-desktop:~$ sudo iptables -A INPUT -p tcp --dport 631 -j DROP
dmarescajr@dmarescajr-desktop:~$ sudo iptables-save