Rules which work well as router on Ubuntu Mate

# Generated by iptables-save v1.6.0 on Wed Jan 17 12:57:59 2018
*filter
:INPUT ACCEPT [3042716:316035492]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [2584596:185631118]
#-A FORWARD -i enxb827ebaced3e -o tun0 -m state --state RELATED,ESTABLISHED  -j ACCEPT
-A FORWARD -i enxb827ebaced3e -o tun0   -j ACCEPT
COMMIT
#sshguard - [0:0]
#-A INPUT -j sshguard
*nat
:PREROUTING ACCEPT [23978:1493968]
:INPUT ACCEPT [107:30172]
:OUTPUT ACCEPT [1193:75732]
:POSTROUTING ACCEPT [302:21040]
#-A POSTROUTING -o tun0 -j MASQUERADE
COMMIT
# Completed on Wed Jan 17 12:57:59 2018
me@me-desktop:/etc/iptables$