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

auto ens18
iface ens18 inet static
 address 10.82.1.211
 netmask 255.255.0.0
 gateway 10.82.0.1

auto dummy0
iface dummy0 inet static
 address 192.168.33.1
 netmask 255.255.255.0
 pre-up ip link add dummy0 type dummy

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

Ipfordward on

• cat /etc/sysctl.conf

net.ipv4.ip_forward=1

• sysctl -p

Manual

garlic

• ip tunnel add gretun mode gre remote 10.82.1.195 local 10.82.1.211 ttl 255
• ip address add dev gretun 172.30.30.1 peer 172.30.30.2/32
• ip link set gretun up
• ip route add 192.168.55.0/24 via 172.30.30.2

hubsi

• ip tunnel add gretun mode gre remote 10.82.1.211 local 10.82.1.195 ttl 255
• ip address add dev gretun 172.30.30.2 peer 172.30.30.1/32
• ip link set gretun up
• ip route add 192.168.33.0/24 via 172.30.30.1

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