Gre tunnel linux

Layout

-192.168.33.1/24 -|garlic|-10.82.1.211---------------------10.82.1.195-|hubsi|-192.168.55.1/24

Interfaces

garlic

#WAN
auto eth0
iface eth0 inet static
 address 10.82.1.211
 netmask 255.255.0.0
 gateway 10.82.0.1
#LAN
auto eth1
iface eth1 inet static
 address 192.168.33.1
 netmask 255.255.255.0

hubsi

auto ens18
iface ens18 inet static
 address 10.82.1.195
 netmask 255.255.0.0
 gateway 10.82.0.1

auto dummy0
iface dummy0 inet static
 address 192.168.55.1
 netmask 255.255.255.0
 pre-up ip link add dummy0 type dummy

Ipforward on

• cat /etc/sysctl.conf

net.ipv4.ip_forward=1

• sysctl -p

Static

garlic

auto  gretun
iface gretun inet static
  address 172.30.30.1
  pointopoint 172.30.30.2
  pre-up ip tunnel add gretun mode gre remote 10.82.1.195 local 10.82.1.211 ttl 255
  post-up ip route add 192.168.55.0/24 via 172.30.30.2

hubsi

auto  gretun
iface gretun inet static
  address 172.30.30.2
  pointopoint 172.30.30.1
  pre-up ip tunnel add gretun mode gre remote 10.82.1.211 local 10.82.1.195 ttl 255
  post-up ip route add 192.168.33.0/24 via 172.30.30.1