Merge pull request #4715 from c-po/ethernet-if-removal

ethernet: T7813: remove VLAN interfaces first on deletion

2 files changed, 15 insertions, 9 deletions

diff --git a/python/vyos/ifconfig/ethernet.py b/python/vyos/ifconfig/ethernet.py
index 864a9d0bc..6c7b230ca 100644
--- a/python/vyos/ifconfig/ethernet.py
+++ b/python/vyos/ifconfig/ethernet.py
@@ -131,19 +131,17 @@ class EthernetIf(Interface):
         >>> i.remove()
         """
 
+        # T7813: we do need to remove the VLAN subinterfaces first so we can
+        # properly stop the DHCP client and inform the DHCP server that we are
+        # returning the lease.
+        for vlan in Section.sub_interfaces(self.ifname):
+            Interface(vlan).remove()
+
         if self.exists(self.ifname):
             # interface is placed in A/D state when removed from config! It
             # will remain visible for the operating system.
             self.set_admin_state('down')
 
-        # Remove all VLAN subinterfaces - filter with the VLAN dot
-        for vlan in [
-            x
-            for x in Section.interfaces('ethernet')
-            if x.startswith(f'{self.ifname}.')
-        ]:
-            Interface(vlan).remove()
-
         super().remove()
 
     def set_flow_control(self, enable):
diff --git a/python/vyos/ifconfig/section.py b/python/vyos/ifconfig/section.py
index 4ea606495..201494736 100644
--- a/python/vyos/ifconfig/section.py
+++ b/python/vyos/ifconfig/section.py
@@ -144,10 +144,18 @@ class Section:
         if no section is provided, then it returns all configured interfaces.
         If vlan is True, also Vlan subinterfaces will be returned
         """
-
         return cls._sort_interfaces(cls._intf_under_section(section, vlan))
 
     @classmethod
+    def sub_interfaces(cls, interface : str) -> list:
+        """
+        return a list of subinterfaces (e.g. VLAN) derived from a given interface
+        """
+        if_type = cls.section(interface)
+        res = [x for x in cls.interfaces(if_type) if x.startswith(f'{interface}.')]
+        return res
+
+    @classmethod
     def _intf_with_feature(cls, feature=''):
         """
         return a generator with the name of the configured interface which have