Resources:
[archwiki-internet-sharing](https://wiki.archlinux.org/title/Internet_sharing#Configuration)
[archwiki-sysctl](https://wiki.archlinux.org/title/Sysctl#Configuration)
[kernel-sysctl](https://www.kernel.org/doc/html/latest//networking/ip-sysctl.html)

Remark: Many resources mention that all #firewall config should be executed in one go from a script.
They also mention to make sure to flush all previous rules/tables/chains before beginning the setup.
Order of rules matter.

*Check current settings*
```bash
sudo sysctl -a | grep forward
```

# Config 
```
net.ipv4.conf.all.bc_forwarding = 0 # broadcast?
net.ipv4.conf.all.forwarding = 1 # Enable IP forwarding on this interface.
```
Latter above controls whether packets received _on_ this (in this case on _all_) interface can be forwarded.

```
net.ipv4.conf.all.mc_forwarding = 0 # Multicast routing
```
## Locations
### Preloaded

# Tags
#firewall #nat
#sysctl
#ip-forwarding
#masquerading