diff --git a/junos/interfaces.nix b/junos/interfaces.nix
new file mode 100644
index 0000000..f5094a8
--- /dev/null
+++ b/junos/interfaces.nix
@@ -0,0 +1,128 @@
+{ lib, config, ... }:
+with lib;
+let
+  interface =
+    { name, config, ... }:
+    let
+      intf-name = name;
+      unit =
+        { name, config, ... }:
+        {
+          options = {
+            enable = mkEnableOption "the logical interface ${intf-name}.${name}" // { default = true; };
+            family = {
+              ethernet-switching = {
+                enable = mkEnableOption "the ethernet on the logical interface ${intf-name}.${name}";
+                interface-mode = mkOption {
+                  type = types.nullOr (
+                    types.enum [
+                      "trunk"
+                      "access"
+                    ]
+                  );
+                  default = null;
+                };
+                vlans = mkOption {
+                  type = types.listOf (types.either types.str types.ints.unsigned);
+                  default = [ ];
+                };
+              };
+              #TODO : DHCP
+              inet = {
+                enable = mkEnableOption "the IPv4 configuration of the logical interface ${intf-name}.${name}";
+                address = mkOption {
+                  type = types.listOf types.str;
+                  default = [ ];
+                };
+              };
+              inet6 = {
+                enable = mkEnableOption "the IPv6 configuration of the logical interface ${intf-name}.${name}";
+                address = mkOption {
+                  type = types.listOf types.str;
+                  default = [ ];
+                };
+              };
+            };
+            xml = mkOption {
+              type = types.str;
+              visible = false;
+              readOnly = true;
+            };
+          };
+          config.xml =
+            let
+              members = map (
+                vlan: "<members>${builtins.toString vlan}</members>"
+              ) config.family.ethernet-switching.vlans;
+              eth = optionalString config.family.ethernet-switching.enable ''
+                <ethernet-switching>
+                  <interface-mode>${config.family.ethernet-switching.interface-mode}</interface-mode>
+                  <vlan>${builtins.concatStringsSep "" members}</vlan>
+                  <storm-control><profile-name>default</profile-name></storm-control>
+                </ethernet-switching>
+              '';
+
+              addr4 = map (addr: "<name>${addr}</name>") config.family.inet.address;
+              inet = optionalString config.family.inet.enable ''
+                <inet>
+                  <address>${builtins.concatStringsSep "" addr4}</address>
+                </inet>
+              '';
+
+              addr6 = map (addr: "<name>${addr}</name>") config.family.inet6.address;
+              inet6 = optionalString config.family.inet6.enable ''
+                <inet6>
+                  <address>${builtins.concatStringsSep "" addr6}</address>
+                </inet6>
+              '';
+            in
+            ''
+              <unit>
+                <name>${name}</name>
+                ${optionalString (!config.enable) "<disable/>"}
+                <family>
+                  ${eth}${inet}${inet6}
+                </family>
+              </unit>'';
+        };
+    in
+    {
+      options = {
+        enable = mkEnableOption "the physical interface ${intf-name}";
+        unit = mkOption { type = types.attrsOf (types.submodule unit); default = {}; };
+        xml = mkOption {
+          type = types.str;
+          visible = false;
+          readOnly = true;
+        };
+      };
+      config.xml =
+        let
+          units = attrsets.mapAttrsToList (_: unit: unit.xml) config.unit;
+        in
+        ''
+          <interface>
+            <name>${name}</name>
+            ${optionalString (!config.enable) "<disable/>"}
+            ${builtins.concatStringsSep "" units}
+          </interface>
+        '';
+    };
+in
+{
+  options = {
+    interfaces = mkOption { type = types.attrsOf (types.submodule interface); };
+    netconf.xmls.interfaces = mkOption {
+      type = types.str;
+      visible = false;
+      readOnly = true;
+    };
+  };
+  config.netconf.xmls.interfaces = ''
+    <interfaces operation="replace">
+      ${
+        builtins.concatStringsSep "" (attrsets.mapAttrsToList (_: intf: intf.xml) config.interfaces)
+      }
+    </interfaces>
+  '';
+}