Original iptables Setup

*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -i enp3s0 -p tcp -s 10.64.32.0/24 --dport 22 -j ACCEPT
-A INPUT -i enp3s0 -p tcp -s 10.64.32.0/24 --dport 53 -j ACCEPT
-A INPUT -i enp3s0 -p udp -s 10.64.32.0/24 --dport 53 -j ACCEPT
-A INPUT -i enp3s0 -p udp -s 10.64.32.0/24 --sport 68 --dport 67 -j ACCEPT
-A INPUT -i enp3s0 -p tcp -s 10.64.32.0/24 --dport 80 -j ACCEPT
-A INPUT -i enp0s20u1u3  -p udp -s 10.64.32.0/24 --sport 67 --dport 67 -j ACCEPT

-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -i enp0s20u1u3 -o enp3s0 -p tcp -d 10.63.32.10 --dport 443 -j ACCEPT
-A FORWARD -i enp3s0 -o enp0s20u1u3 -j ACCEPT

# Default rules:
-A INPUT -p icmp -j ACCEPT
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -j REJECT --reject-with tcp-reset
-A INPUT -p udp -j REJECT --reject-with icmp-port-unreachable
-A INPUT -j REJECT --reject-with icmp-proto-unreachable
COMMIT

*nat
:PREROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
-A PREROUTING -i enp0s20u1u3 -p tcp --dport 443 -j DNAT --to 10.64.32.10:443

-A POSTROUTING -s 10.64.32.0/24 -o enp0s20u1u3 -j MASQUERADE
COMMIT