network

https://rtcamp.com/tutorials/linux/sysctl-conf/

https://wiki.ubuntu.com/ImprovedNetworking/KernelSecuritySettings

zonas - https://openwrt.org/docs/guide-user/firewall/firewall_configuration#zon…
https://openwrt.org/docs/guide-user/firewall/start

https://openwrt.org/docs/guide-user/firewall/fw3_configurations/interce…

https://www.tecmint.com/increase-linux-server-internet-speed-with-tcp-b…
https://github.com/google/bbr

https://bobcares.com/blog/iptables-udp-port-forwarding/

https://openwrt.org/docs/guide-user/network/wifi/dumbap

https://www.tutorialandexample.com/variable-length-subnet-masks-vlsms/

auto lo
iface lo inet loopback

# eno1 is my physical network adapter name.
# Change 'eno1' *everywhere* in this file for your adapter name.
auto eno1
iface eno1 inet manual
post-up echo 1 > /proc/sys/net/ipv4/conf/eno1/proxy_arp

no artigo do link https://unix.stackexchange.com/questions/282086/how-does-nat-reflection… é explicado o nat reflection.

quando criamos um encaminhamento para uma máquina numa zona (lan, por exemplo) o openwrt cria as regras de nat reflection automaticamente. para as visualizarmos executamos:
iptables-save -c | grep reflection

e o resultado: