Did you enable forwarding via sysctl?
sysctl net.ipv4.ip_forward
This should report 1
Did you enable forwarding via sysctl?
sysctl net.ipv4.ip_forward
This should report 1
You only need the masquerade rule.
iptables -t nat -A POSTROUTING -s 10.11.13.0/24 -o enp3s0 -j MASQUERADE
ext4 + mdadm + dm-integrity would solve the bit rot problem. But you’d end up with a lot of parts bolted together and still miss out on the features that btrfs/zfs provide.
OpenOffice is a zombie at this point.