1. $ cat /usr/bin/startnat.sh
  2. #!/bin/bash
  4. INTERNAL=eth0
  5. EXTERNAL=eth1
  8. echo 1 > /proc/sys/net/ipv4/ip_forward
  9. /sbin/iptables -t nat -A POSTROUTING -o $EXTERNAL -j MASQUERADE
  10. /sbin/iptables -A FORWARD -i $EXTERNAL -o $INTERNAL -m state --state RELATED,ESTABLISHED -j ACCEPT
  11. /sbin/iptables -A FORWARD -i $INTERNAL -o $EXTERNAL -j ACCEPT
  13. --------------------------------------------------------------------------------------------------------------
  15. pi@raspberrypi:~ $ cat /etc/network/interfaces
  16. # interfaces(5) file used by ifup(8) and ifdown(8)
  18. # Please note that this file is written to be used with dhcpcd
  19. # For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
  21. # Include files from /etc/network/interfaces.d:
  22. source-directory /etc/network/interfaces.d
  23. post-up /usr/bin/startnat.sh