diff --git a/_modules/node.py b/_modules/node.py
--- a/_modules/node.py
+++ b/_modules/node.py
@@ -259,3 +259,59 @@
         return private_network
 
     return network
+
+
+def _resolve_gre_tunnels_for_router(network, netmask):
+    tunnels = []
+
+    for node, tunnel in __pillar__.get(f"{network}_gre_tunnels", {}).items():
+        tunnels.append(
+            {
+                "description": f"{network}_to_{node}",
+                "interface": tunnel["router"]["interface"],
+                "src": tunnel["router"]["addr"],
+                "dst": tunnel["node"]["addr"],
+                "netmask": netmask,
+                "icann_src": get("network")["canonical_public_ipv4"],
+                "icann_dst": get("network", node)["canonical_public_ipv4"],
+            }
+        )
+
+    return tunnels
+
+
+def resolve_gre_tunnels():
+    """
+    A function to get the GRE tunnels for a node
+
+    CLI Example:
+        salt * node.resolve_gre_tunnels
+    """
+    gre_tunnels = []
+
+    for network, network_args in __pillar__.get("networks", {}).items():
+        if __grains__["id"] == network_args["router"]:
+            gre_tunnels += _resolve_gre_tunnels_for_router(
+                network, network_args["netmask"]
+            )
+            continue
+
+        tunnel = __salt__["pillar.get"](f"{network}_gre_tunnels:{__grains__['id']}")
+        if not tunnel:
+            continue
+
+        gre_tunnels.append(
+            {
+                "description": f"{network}_via_{network_args['router']}",
+                "interface": tunnel["node"].get("interface", "gre0"),
+                "src": tunnel["node"]["addr"],
+                "dst": tunnel["router"]["addr"],
+                "netmask": network_args["netmask"],
+                "icann_src": get("network")["canonical_public_ipv4"],
+                "icann_dst": get("network", network_args["router"])[
+                    "canonical_public_ipv4"
+                ],
+            }
+        )
+
+    return gre_tunnels
diff --git a/pillar/core/network.sls b/pillar/core/network.sls
--- a/pillar/core/network.sls
+++ b/pillar/core/network.sls
@@ -1,29 +1,49 @@
 networks:
   drake:
     netmask: 255.255.255.0
-    addr:
-      cloudhugger: 172.27.27.28
-      router-001: 172.27.27.1
-      windriver: 172.27.27.35
-      ysul: 172.27.27.33
+    router: router-001
 
-gre_tunnels:
-  windriver:
-    wind-cloud:
-      interface: gre0
-      network: drake
-      to: cloudhugger
-
-    wind-ysul:
-      interface: gre0
-      network: drake
-      to: ysul
+#   -------------------------------------------------------------
+#   Drake - GRE tunnels
+#
+#   Describe GRE tunnels between a node and {networks.drake.router}
+#
+#   {id}:
+#   router:
+#       interface: gre0, gre1, ... / increment for each tunnel
+#       addr:      The tunnel IPv4 on the router in 172.27.27.240/28
+#
+#     node:
+#       interface: Not needed on Linux as the interface name will be
+#                  descriptive: gre-drake_via_{networks.drake.router}
+#
+#                  Not needed on FreeBSD if default value "gre0" is fine.
+#                  If there is several GRE tunnels, can be gre1, gre2, etc.
+#
+#       addr:      The canonical IPv4 for the server in 172.27.27.0/24
+#
+#   IP should be sync between the pillar and the Operations grimoire
+#   at https://agora.nasqueron.org/Operations_grimoire/Network
+#   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+drake_gre_tunnels:
   ysul:
-    wind-ysul: &gre_drake_to_windriver
+    router:
       interface: gre0
-      network: drake
-      to: windriver
+      addr: 172.27.27.252
+    node:
+      addr: 172.27.27.33
 
   cloudhugger:
-    wind-cloud: *gre_drake_to_windriver
+    router:
+      interface: gre1
+      addr: 172.27.27.253
+    node:
+      addr: 172.27.27.28
+
+  windriver:
+    router:
+      interface: gre2
+      addr: 172.27.27.254
+    node:
+      addr: 172.27.27.35
diff --git a/roles/core/network/gre.sls b/roles/core/network/gre.sls
--- a/roles/core/network/gre.sls
+++ b/roles/core/network/gre.sls
@@ -6,51 +6,26 @@
 #   License:        Trivial work, not eligible to copyright
 #   -------------------------------------------------------------
 
-{% set network = salt['node.get']('network') %}
-{% set gre_tunnels = salt['pillar.get']("gre_tunnels:" + grains['id'], {}) %}
+{% from "roles/core/network/map.jinja" import gre with context %}
 {% set boot_loader = namespace(gre=false) %}
 
 #   -------------------------------------------------------------
 #   Tunnels network configuration files
 #   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-{% for description, tunnel in gre_tunnels.items() %}
+{% for tunnel in salt['node.resolve_gre_tunnels']() %}
 
 {% set boot_loader.gre = True %}
-{% set tunnel_network = pillar['networks'][tunnel['network']] %}
 
-{% if grains['os'] == 'FreeBSD' %}
-/etc/rc.conf.d/netif/gre_{{ description }}:
+{{ gre.config_path }}{{ tunnel["description"] }}:
   file.managed:
-    - source: salt://roles/core/network/files/FreeBSD/netif_gre.rc
+    - source: salt://roles/core/network/files/{{ gre.source_path }}
     - makedirs: True
     - template: jinja
-    - context:
-        description: {{ description }}
-        interface: {{ tunnel['interface'] }}
-
-        src: {{ tunnel_network['addr'][grains['id']] }}
-        dst: {{ tunnel_network['addr'][tunnel['to']] }}
-
-        icann_src: {{ network['ipv4_address'] }}
-        icann_dst: {{ salt['node.get']('network', tunnel['to'])['ipv4_address'] }}
-{% endif %}
-
+    - defaults: {{ tunnel }}
 {% if grains['os_family'] == 'Debian' %}
-/etc/network/interfaces.d/10-gre-{{ description }}:
-  file.managed:
-    - source: salt://roles/core/network/files/Debian/10-gre.jinja
-    - makedirs: True
-    - template: jinja
     - context:
         interface: gre-{{ description }}
-
-        src: {{ tunnel_network['addr'][grains['id']] }}
-        dst: {{ tunnel_network['addr'][tunnel['to']] }}
-        netmask: {{ tunnel_network['netmask'] }}
-
-        icann_src: {{ network['ipv4_address'] }}
-        icann_dst: {{ salt['node.get']('network', tunnel['to'])['ipv4_address'] }}
 {% endif %}
 
 {% endfor %}
diff --git a/roles/core/network/map.jinja b/roles/core/network/map.jinja
--- a/roles/core/network/map.jinja
+++ b/roles/core/network/map.jinja
@@ -32,3 +32,20 @@
     "suffix": "device",
   },
 }) %}
+
+#   -------------------------------------------------------------
+#   GRE tunnels configuration by OS/distro
+#
+#   See interface configuration for the documentation.
+#   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+{% set gre = salt['grains.filter_by']({
+  'FreeBSD': {
+    "config_path": "/etc/rc.conf.d/netif/gre_",
+    "source_path": "FreeBSD/netif_gre.rc",
+  },
+  'Debian': {
+    "config_path": "/etc/network/interfaces.d/10-gre-",
+    "source_path": "Debian/10-gre.jinja",
+  },
+}) %}