diff --git a/.pylintrc b/.pylintrc
index 646c5ae..67808cd 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -14,7 +14,7 @@ ignore-patterns=test_.*
 #   W1203 = Use lazy % formatting in logging functions
 
 # Disable the message(s) with the given id(s).
-disable=R0201,W0212,W0613,C0301,R0914,C0111,W1203
+disable=R0201,W0212,W0613,C0301,R0914,W1203
 
 [FORMAT]
 max-line-length=148
diff --git a/config/__init__.py b/config/__init__.py
index 1e4365b..360fc43 100644
--- a/config/__init__.py
+++ b/config/__init__.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 #
 # -*- coding: utf-8 -*-
+""" A vppcfg configuration module that exposes its semantic/syntax validators """
 from __future__ import (
     absolute_import,
     division,
@@ -66,6 +67,15 @@ class IPInterfaceWithPrefixLength(Validator):
 
 
 class Validator:
+    """The Validator class takes a schema filename (which may be None, in which
+    case a built-in default is used), and a given YAML file represented as a string,
+    and holds it against syntax and semantic validators, returning a tuple of (bool,list)
+    where the boolean signals success/failure, and the list of strings are messages
+    that were added when validating the YAML config.
+
+    The purpose is to  ensure that the YAML file is both syntactically correct,
+    which is ensured by Yamale, and semantically correct, which is ensured by a set
+    of built-in validators, and user-added validators (see the add_validator() method)."""
     def __init__(self, schema):
         self.logger = logging.getLogger("vppcfg.config")
         self.logger.addHandler(logging.NullHandler())
@@ -81,6 +91,8 @@ class Validator:
         ]
 
     def validate(self, yaml):
+        """Validate the semantics of all YAML maps, by calling self.validators in turn,
+        and then optionally calling validators that were added with add_validator()"""
         ret_retval = True
         ret_msgs = []
         if not yaml:
diff --git a/config/address.py b/config/address.py
index 46776d5..2afa3d9 100644
--- a/config/address.py
+++ b/config/address.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that handles addresses """
 import ipaddress
 
 
diff --git a/config/bondethernet.py b/config/bondethernet.py
index 26bc79b..6ef17df 100644
--- a/config/bondethernet.py
+++ b/config/bondethernet.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that handles bondethernets """
 import logging
 from config import interface
 from config import mac
@@ -162,6 +163,7 @@ def int_to_lb(loadbalance):
 
 
 def validate_bondethernets(yaml):
+    """Validate the semantics of all YAML 'bondethernets' entries"""
     result = True
     msgs = []
     logger = logging.getLogger("vppcfg.config")
diff --git a/config/bridgedomain.py b/config/bridgedomain.py
index bed5c5c..fd0b634 100644
--- a/config/bridgedomain.py
+++ b/config/bridgedomain.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that handles bridgedomains """
 import logging
 from config import interface
 from config import loopback
@@ -81,6 +82,8 @@ def bvi_unique(yaml, bviname):
 
 
 def get_settings(yaml, ifname):
+    """Return a dictionary of 'settings' including their VPP defaults, for the
+    bridgedomain identified by 'ifname' (bd10)"""
     ifname, iface = get_by_name(yaml, ifname)
     if not iface:
         return None
@@ -115,6 +118,7 @@ def get_settings(yaml, ifname):
 
 
 def validate_bridgedomains(yaml):
+    """Validate the semantics of all YAML 'bridgedomains' entries"""
     result = True
     msgs = []
     logger = logging.getLogger("vppcfg.config")
diff --git a/config/interface.py b/config/interface.py
index 6ecdad9..6ff671a 100644
--- a/config/interface.py
+++ b/config/interface.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that validates interfaces """
 import logging
 from config import bondethernet
 from config import bridgedomain
@@ -415,6 +416,7 @@ def get_admin_state(yaml, ifname):
 
 
 def validate_interfaces(yaml):
+    """Validate the semantics of all YAML 'interfaces' entries"""
     result = True
     msgs = []
     logger = logging.getLogger("vppcfg.config")
diff --git a/config/lcp.py b/config/lcp.py
index 57d76f3..13a8c35 100644
--- a/config/lcp.py
+++ b/config/lcp.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that validates Linux Control Plane (lcp) elements """
 
 
 def get_lcps(yaml, interfaces=True, loopbacks=True, bridgedomains=True):
diff --git a/config/loopback.py b/config/loopback.py
index 92b981c..3bb1d33 100644
--- a/config/loopback.py
+++ b/config/loopback.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that validates loopbacks """
 import logging
 from config import lcp
 from config import address
@@ -53,6 +54,7 @@ def is_loopback(yaml, ifname):
 
 
 def validate_loopbacks(yaml):
+    """Validate the semantics of all YAML 'loopbacks' entries"""
     result = True
     msgs = []
     logger = logging.getLogger("vppcfg.config")
diff --git a/config/mac.py b/config/mac.py
index 89135b9..1f36e83 100644
--- a/config/mac.py
+++ b/config/mac.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that validates MAC addresses """
 import netaddr
 
 
diff --git a/config/tap.py b/config/tap.py
index 9e40b30..ee89dcf 100644
--- a/config/tap.py
+++ b/config/tap.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that validates taps """
 import logging
 from config import mac
 
@@ -54,6 +55,7 @@ def is_host_name_unique(yaml, hostname):
 
 
 def validate_taps(yaml):
+    """Validate the semantics of all YAML 'taps' entries"""
     result = True
     msgs = []
     logger = logging.getLogger("vppcfg.config")
diff --git a/config/test_bondethernet.py b/config/test_bondethernet.py
index 5faebea..cbc5e0b 100644
--- a/config/test_bondethernet.py
+++ b/config/test_bondethernet.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for bondethernet """
 import unittest
 import yaml
 import config.bondethernet as bondethernet
diff --git a/config/test_bridgedomain.py b/config/test_bridgedomain.py
index f9be7ad..e415490 100644
--- a/config/test_bridgedomain.py
+++ b/config/test_bridgedomain.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for bridgedomains """
 import unittest
 import yaml
 import config.bridgedomain as bridgedomain
diff --git a/config/test_interface.py b/config/test_interface.py
index 8c61a48..210043b 100644
--- a/config/test_interface.py
+++ b/config/test_interface.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for interfaces """
 import unittest
 import yaml
 import config.interface as interface
diff --git a/config/test_lcp.py b/config/test_lcp.py
index 6721ed2..3f3a1c4 100644
--- a/config/test_lcp.py
+++ b/config/test_lcp.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for LCPs """
 import unittest
 import yaml
 import config.lcp as lcp
diff --git a/config/test_loopback.py b/config/test_loopback.py
index 8d27d00..591a08c 100644
--- a/config/test_loopback.py
+++ b/config/test_loopback.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for loopbacks """
 import unittest
 import yaml
 import config.loopback as loopback
diff --git a/config/test_mac.py b/config/test_mac.py
index 89773dd..2a079be 100644
--- a/config/test_mac.py
+++ b/config/test_mac.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for MAC addresses """
 import unittest
 import config.mac as mac
 
diff --git a/config/test_tap.py b/config/test_tap.py
index 5af3e4f..cc804e5 100644
--- a/config/test_tap.py
+++ b/config/test_tap.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for taps """
 import unittest
 import yaml
 import config.tap as tap
diff --git a/config/test_vxlan_tunnel.py b/config/test_vxlan_tunnel.py
index 2a1e7de..9f5c4aa 100644
--- a/config/test_vxlan_tunnel.py
+++ b/config/test_vxlan_tunnel.py
@@ -1,3 +1,18 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
+""" Unit tests for vxlan_tunnels """
 import unittest
 import yaml
 import config.vxlan_tunnel as vxlan_tunnel
diff --git a/config/vxlan_tunnel.py b/config/vxlan_tunnel.py
index 0811cce..9c7202d 100644
--- a/config/vxlan_tunnel.py
+++ b/config/vxlan_tunnel.py
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+""" A vppcfg configuration module that validates vxlan_tunnels """
 import logging
 import ipaddress
 
@@ -56,6 +57,7 @@ def get_vxlan_tunnels(yaml):
 
 
 def validate_vxlan_tunnels(yaml):
+    """Validate the semantics of all YAML 'vxlan_tunnels' entries"""
     result = True
     msgs = []
     logger = logging.getLogger("vppcfg.config")
diff --git a/tests.py b/tests.py
index de8cecf..0bf4118 100755
--- a/tests.py
+++ b/tests.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 #
 # -*- coding: utf-8 -*-
+""" This is a unit test suite for vppcfg """
 
 import sys
 import glob
@@ -36,6 +37,8 @@ def example_validator(_yaml):
 
 
 class YAMLTest(unittest.TestCase):
+    """This test suite takes a YAML configuration file and holds it against the syntax
+    (Yamale) and semantic validators, returning errors in case of validation failures."""
     def __init__(self, testName, yaml_filename, yaml_schema):
         # calling the super class init varies for different python versions.  This works for 2.7
         super().__init__(testName)
@@ -43,6 +46,7 @@ class YAMLTest(unittest.TestCase):
         self.yaml_schema = yaml_schema
 
     def test_yaml(self):
+        """ The test executor """
         test = None
         cfg = None
         ncount = 0
@@ -103,6 +107,7 @@ class YAMLTest(unittest.TestCase):
 
 
 if __name__ == "__main__":
+    """ The main program """
     parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter)
     parser.add_argument(
         "-t",
diff --git a/vpp/applier.py b/vpp/applier.py
index d451fea..2483f76 100644
--- a/vpp/applier.py
+++ b/vpp/applier.py
@@ -1,3 +1,17 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
 """
 The functions in this file interact with the VPP API to modify certain
 interface metadata.
@@ -18,31 +32,45 @@ class Applier(VPPApi):
         self.logger.info("VPP Applier: changing the dataplane is enabled")
 
     def set_interface_ip_address(self, ifname, address, is_set=True):
+        """Add (if_set=True) or remove (if_set=False) an IPv4 or IPv6 address including
+        prefixlen (ie 192.0.2.0/24 or 2001:db8::1/64) to an interface given by name
+        (ie GigabitEthernet3/0/0)"""
         pass
 
     def delete_loopback(self, ifname):
+        """Delete a loopback identified by name (ie loop0)"""
         pass
 
     def delete_subinterface(self, ifname):
+        """Delete a sub-int identified by name (ie GigabitEthernet3/0/0.100)"""
         pass
 
-    def set_interface_l2_tag_rewrite(self, ifname, mode):
+    def set_interface_l2_tag_rewrite(self, ifname, vtr_op, vtr_push_dot1q, vtr_tag1, vtr_tag2):
+        """Set l2 tag rewrite on an interface identified by name (ie GigabitEthernet3/0/0.100)
+        into a certain operational mode. TODO(pim) clarify the vtr_* arguments."""
         ## somewhere in interface.api see vtr_* fields
         pass
 
     def set_interface_l3(self, ifname):
+        """Set an interface or sub-interface identified by name (ie GigabitEthernet3/0/0)
+        to L3 mode, removing it from bridges and l2xcs"""
         pass
 
-    def delete_bridgedomain(self, instance):
+    def delete_bridgedomain(self, bd_id):
+        """Delete a bridgedomain given by instance bd_id (ie 100). Cannot delete instance==0."""
         pass
 
     def delete_tap(self, ifname):
+        """Delete a tap identified by name (ie tap100)"""
         pass
 
     def bond_remove_member(self, bondname, membername):
+        """Remove a member interface given by name (ie GigabitEthernet3/0/0) from a bondethernet
+        interface given by name (ie BondEthernet0)"""
         pass
 
     def delete_bond(self, ifname):
+        """Delete a bondethernet identified by name (ie BondEthernet0)"""
         pass
 
     def create_vxlan_tunnel(self, instance, config, is_create=True):
@@ -50,15 +78,22 @@ class Applier(VPPApi):
         pass
 
     def set_interface_link_mtu(self, ifname, link_mtu):
+        """Set the max frame size of an interface given by name to the link_mtu value (typically
+        1500, 9000, 9216"""
+
         pass
 
     def lcp_delete(self, lcpname):
+        """Delete a linux control plane interface pair by name (ie 'xe0' or 'be10')"""
         pass
 
     def set_interface_packet_mtu(self, ifname, packet_mtu):
+        """Set the L3 MTU of an interface given by name (ie GigabitEthernet3/0/0)"""
         pass
 
     def set_interface_state(self, ifname, state):
+        """Set the admin link state (True is up, False is down) of an interface given
+        by name (ie GigabitEthernet3/0/0)"""
         pass
 
     def create_loopback_interface(self, instance, config):
@@ -77,28 +112,43 @@ class Applier(VPPApi):
         """'config' is the YAML configuration for the taps: entry"""
         pass
 
-    def create_bridgedomain(self, instance, config):
+    def create_bridgedomain(self, bd_id, config):
         """'config' is the YAML configuration for the bridgedomains: entry"""
         pass
 
     def lcp_create(self, ifname, host_if_name):
+        """Create a linux control plane interface pair for an interface given by name
+        (ie GigabitEthernet3/0/0) under a Linux TAP device name host_if_name (ie e3-0-0)"""
         pass
 
     def set_interface_mac(self, ifname, mac):
+        """Set the MAC address of interface given by name (ie GigabitEthernet3/0/0), the
+        MAC is of form aa:bb:cc:dd:ee:ff"""
         pass
 
     def bond_add_member(self, bondname, membername):
+        """Add a member interface given by name (ie GigabitEthernet3/0/0) to a bondethernet
+        given by name (ie BondEthernet0)"""
         pass
 
-    def sync_bridgedomain(self, instance, config):
+    def sync_bridgedomain(self, bd_id, config):
         """'config' is the YAML configuration for the bridgedomains: entry"""
         pass
 
-    def set_interface_l2_bridge_bvi(self, instance, ifname):
+    def set_interface_l2_bridge_bvi(self, bd_id, ifname):
+        """Set a loopback / BVI interface given by name (ie 'loop100') as a BVI of a bridge
+        domain identified by bd_id (ie 100)"""
         pass
 
-    def set_interface_l2_bridge(self, instance, ifname):
+    def set_interface_l2_bridge(self, bd_id, ifname):
+        """Set an interface given by name (ie 'GigabitEthernet3/0/0') into a bridge 
+        domain identified by bd_id (ie 100)"""
         pass
 
     def set_interface_l2xc(self, rx_ifname, tx_ifname):
+        """Cross connect the rx_ifname (ie GigabitEthernet3/0/0) to emit into the tx_ifname
+        (ie GigabitEthernet3/0/1). Note that this operation typically happens twice, once
+        for the a->b crossconnect, and again for the b->a crossconnect. Note that
+        crossconnecting sub-interfaces requires as well L2 rewriting (pop N for the amount
+        of tags on the source interface)"""
         pass
diff --git a/vpp/dumper.py b/vpp/dumper.py
index 77a247b..1bd3809 100644
--- a/vpp/dumper.py
+++ b/vpp/dumper.py
@@ -1,3 +1,17 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
 """
 The functions in this file interact with the VPP API to retrieve certain
 interface metadata and write it to a YAML file.
@@ -10,10 +24,17 @@ from config import bondethernet
 
 
 class Dumper(VPPApi):
+    """The Dumper class first reads the configuration from a running VPP Dataplane
+    by using a set of (readonly) API getters, and then emits the configuration as
+    a YAML file with its write() method, either to stdout or to a filename.
+
+    Note that not all running VPP configs are "valid" in vppcfg's eyes. It is not
+    guaranteed that the output of the Dumper() will stand validation."""
     def __init__(self, address="/run/vpp/api.sock", clientname="vppcfg"):
         VPPApi.__init__(self, address, clientname)
 
     def write(self, outfile):
+        """ Emit the configuration to either stdout (outfile=='-') or a filename """
         if outfile and outfile == "-":
             file = sys.stdout
             outfile = "(stdout)"
@@ -29,6 +50,8 @@ class Dumper(VPPApi):
         self.logger.info(f"Wrote YAML config to {outfile}")
 
     def cache_to_config(self):
+        """ Convert the VPP configuration cache (previously read by readconfig() into
+        a YAML representation."""
         config = {
             "loopbacks": {},
             "bondethernets": {},
diff --git a/vpp/reconciler.py b/vpp/reconciler.py
index 3400220..8eda3e8 100644
--- a/vpp/reconciler.py
+++ b/vpp/reconciler.py
@@ -13,6 +13,10 @@
 # limitations under the License.
 #
 # -*- coding: utf-8 -*-
+"""
+The functions in this file interact with the VPP API to retrieve certain
+metadata, and plan configuration changes towards a given YAML target configuration.
+"""
 import sys
 import logging
 from config import loopback
@@ -26,6 +30,14 @@ from vpp.vppapi import VPPApi
 
 
 class Reconciler:
+    """The Reconciler class first reads the running configuration of a VPP Dataplane,
+    and based on an intended target YAML configuration file, plans a path to make the
+    dataplane safely reflect the target config. It first prunes (removes) objects that
+    are not meant to be in the dataplane, or are in the dataplane but are not of the
+    correct create-time attributes; then it creates objects that are in the configuration
+    but not yet in the dataplane; and finally it syncs the configuration attributes of
+    objects that can be changed at runtime."""
+
     def __init__(self, cfg):
         self.logger = logging.getLogger("vppcfg.reconciler")
         self.logger.addHandler(logging.NullHandler())
@@ -68,12 +80,6 @@ class Reconciler:
                 ret = False
         return ret
 
-    def vpp_readconfig(self):
-        if not self.vpp.readconfig():
-            self.logger.error("Could not (re)read config from VPP")
-            return False
-        return True
-
     def prune(self):
         """Remove all objects from VPP that do not occur in the config. For an indepth explanation
         of how and why this particular pruning order is chosen, see README.md section on
@@ -748,6 +754,7 @@ class Reconciler:
         return ret
 
     def create_loopbacks(self):
+        """Create all loopbacks that occur in the config but not in VPP"""
         for ifname in loopback.get_loopbacks(self.cfg):
             if ifname in self.vpp.cache["interface_names"]:
                 continue
@@ -760,6 +767,7 @@ class Reconciler:
         return True
 
     def create_bondethernets(self):
+        """Create all bondethernets that occur in the config but not in VPP"""
         for ifname in bondethernet.get_bondethernets(self.cfg):
             if ifname in self.vpp.cache["interface_names"]:
                 continue
@@ -776,6 +784,7 @@ class Reconciler:
         return True
 
     def create_vxlan_tunnels(self):
+        """Create all vxlan_tunnels that occur in the config but not in VPP"""
         for ifname in vxlan_tunnel.get_vxlan_tunnels(self.cfg):
             if ifname in self.vpp.cache["interface_names"]:
                 continue
@@ -789,6 +798,7 @@ class Reconciler:
         return True
 
     def create_sub_interfaces(self):
+        """Create all sub-interfaces that occur in the config but not in VPP"""
         ## First create 1-tag (Dot1Q/Dot1AD), and then create 2-tag (Qin*) sub-interfaces
         for do_qinx in [False, True]:
             for ifname in interface.get_sub_interfaces(self.cfg):
@@ -815,6 +825,7 @@ class Reconciler:
         return True
 
     def create_taps(self):
+        """Create all taps that occur in the config but not in VPP"""
         for ifname in tap.get_taps(self.cfg):
             ifname, iface = tap.get_by_name(self.cfg, ifname)
             if ifname in self.vpp.cache["interface_names"]:
@@ -838,6 +849,7 @@ class Reconciler:
         return True
 
     def create_bridgedomains(self):
+        """Create all bridgedomains that occur in the config but not in VPP"""
         for ifname in bridgedomain.get_bridgedomains(self.cfg):
             ifname, _iface = bridgedomain.get_by_name(self.cfg, ifname)
             instance = int(ifname[2:])
@@ -863,6 +875,7 @@ class Reconciler:
         return True
 
     def create_lcps(self):
+        """Create all LCPs that occur in the config but not in VPP"""
         lcpnames = [
             self.vpp.cache["lcps"][x].host_if_name for x in self.vpp.cache["lcps"]
         ]
@@ -900,6 +913,7 @@ class Reconciler:
         return True
 
     def sync(self):
+        """Synchronize the VPP Dataplane configuration for all objects in the config"""
         ret = True
         if not self.sync_loopbacks():
             self.logger.warning("Could not sync Loopbacks in VPP")
@@ -928,6 +942,7 @@ class Reconciler:
         return ret
 
     def sync_loopbacks(self):
+        """Synchronize the VPP Dataplane configuration for loopbacks"""
         for ifname in loopback.get_loopbacks(self.cfg):
             if not ifname in self.vpp.cache["interface_names"]:
                 ## New loopback
@@ -942,6 +957,7 @@ class Reconciler:
         return True
 
     def sync_phys(self):
+        """Synchronize the VPP Dataplane configuration for PHYs"""
         for ifname in interface.get_phys(self.cfg):
             if not ifname in self.vpp.cache["interface_names"]:
                 ## New interface
@@ -956,6 +972,7 @@ class Reconciler:
         return True
 
     def sync_bondethernets(self):
+        """Synchronize the VPP Dataplane configuration for bondethernets"""
         for ifname in bondethernet.get_bondethernets(self.cfg):
             if ifname in self.vpp.cache["interface_names"]:
                 vpp_iface = self.vpp.cache["interface_names"][ifname]
@@ -1008,6 +1025,7 @@ class Reconciler:
         return True
 
     def sync_bridgedomains(self):
+        """Synchronize the VPP Dataplane configuration for bridgedomains"""
         for ifname in bridgedomain.get_bridgedomains(self.cfg):
             instance = int(ifname[2:])
             if instance in self.vpp.cache["bridgedomains"]:
@@ -1097,6 +1115,7 @@ class Reconciler:
         return True
 
     def sync_l2xcs(self):
+        """Synchronize the VPP Dataplane configuration for L2 cross connects"""
         for ifname in interface.get_l2xc_interfaces(self.cfg):
             config_rx_ifname, config_rx_iface = interface.get_by_name(self.cfg, ifname)
             config_tx_ifname, _config_tx_iface = interface.get_by_name(
@@ -1134,6 +1153,9 @@ class Reconciler:
         return True
 
     def sync_mtu_direction(self, shrink=True):
+        """Synchronize the VPP Dataplane packet MTU, where 'shrink' determines the
+        direction (if shrink is True, go from inner-most (QinQ) to outer-most (untagged),
+        and the other direction if shrink is False"""
         if shrink:
             tag_list = [2, 1, 0]
         else:
@@ -1176,6 +1198,9 @@ class Reconciler:
         return True
 
     def sync_link_mtu_direction(self, shrink=True):
+        """Synchronize the VPP Dataplane max frame size (link MTU), where 'shrink' determines the
+        direction (if shrink is True, go from inner-most (QinQ) to outer-most (untagged),
+        and the other direction if shrink is False"""
         for _idx, vpp_iface in self.vpp.cache["interfaces"].items():
             if vpp_iface.sub_number_of_tags != 0:
                 continue
@@ -1231,6 +1256,7 @@ class Reconciler:
         return True
 
     def sync_mtu(self):
+        """Synchronize the VPP Dataplane configuration for interface MTU"""
         ret = True
         if not self.sync_link_mtu_direction(shrink=False):
             self.logger.warning(
@@ -1251,6 +1277,7 @@ class Reconciler:
         return ret
 
     def sync_addresses(self):
+        """Synchronize the VPP Dataplane configuration for interface addresses"""
         for ifname in interface.get_interfaces(self.cfg) + loopback.get_loopbacks(
             self.cfg
         ):
@@ -1279,6 +1306,7 @@ class Reconciler:
         return True
 
     def sync_admin_state(self):
+        """Synchronize the VPP Dataplane configuration for interface admin state"""
         for ifname in interface.get_interfaces(self.cfg) + loopback.get_loopbacks(
             self.cfg
         ):
diff --git a/vpp/vppapi.py b/vpp/vppapi.py
index d2501ad..decc18d 100644
--- a/vpp/vppapi.py
+++ b/vpp/vppapi.py
@@ -1,3 +1,17 @@
+#
+# Copyright (c) 2022 Pim van Pelt
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# -*- coding: utf-8 -*-
 """
 The functions in this file interact with the VPP API to retrieve certain
 interface metadata. Its base class will never change state. See the
@@ -12,6 +26,7 @@ from vpp_papi import VPPApiClient
 
 
 class VPPApi:
+    """The VPPApi class is a base class that abstracts the vpp_papi."""
     def __init__(self, address="/run/vpp/api.sock", clientname="vppcfg"):
         self.logger = logging.getLogger("vppcfg.vppapi")
         self.logger.addHandler(logging.NullHandler())
@@ -25,6 +40,7 @@ class VPPApi:
         self.lcp_enabled = False
 
     def connect(self):
+        """ Connect to the VPP Dataplane, if we're not already connected """
         if self.connected:
             return True
 
@@ -56,6 +72,7 @@ class VPPApi:
         return True
 
     def disconnect(self):
+        """Disconnect from the VPP dataplane, if we are still connected."""
         if not self.connected:
             return True
         self.vpp.disconnect()
@@ -64,6 +81,7 @@ class VPPApi:
         return True
 
     def cache_clear(self):
+        """ Remove the cached VPP configuration elements and return an empty dictionary"""
         self.cache_read = False
         return {
             "lcps": {},
@@ -79,7 +97,7 @@ class VPPApi:
         }
 
     def cache_remove_lcp(self, lcpname):
-        """Removes the LCP and TAP interface, identified by lcpname, from the config."""
+        """Removes the LCP and TAP interface, identified by lcpname, from the VPP config cache"""
         for _idx, lcp in self.cache["lcps"].items():
             if lcp.host_if_name == lcpname:
                 ifname = self.cache["interfaces"][lcp.host_sw_if_index].interface_name
@@ -91,7 +109,7 @@ class VPPApi:
         return False
 
     def cache_remove_bondethernet_member(self, ifname):
-        """Removes the bonderthernet member interface, identified by name, from the config."""
+        """Removes the bonderthernet member interface, identified by name, from the VPP config cache"""
         if not ifname in self.cache["interface_names"]:
             self.logger.warning(
                 f"Trying to remove a bondethernet member interface which is not in the config: {ifname}"
@@ -106,6 +124,7 @@ class VPPApi:
         return True
 
     def cache_remove_l2xc(self, ifname):
+        """Remvoes the l2xc from the VPP config cache"""
         if not ifname in self.cache["interface_names"]:
             self.logger.warning(
                 f"Trying to remove an L2XC which is not in the config: {ifname}"
@@ -116,6 +135,7 @@ class VPPApi:
         return True
 
     def cache_remove_vxlan_tunnel(self, ifname):
+        """Removes a vxlan_tunnel from the VPP config cache"""
         if not ifname in self.cache["interface_names"]:
             self.logger.warning(
                 f"Trying to remove a VXLAN Tunnel which is not in the config: {ifname}"
@@ -127,7 +147,7 @@ class VPPApi:
         return True
 
     def cache_remove_interface(self, ifname):
-        """Removes the interface, identified by name, from the config."""
+        """Removes the interface, identified by name, from the VPP config cache"""
         if not ifname in self.cache["interface_names"]:
             self.logger.warning(
                 f"Trying to remove an interface which is not in the config: {ifname}"
@@ -154,6 +174,8 @@ class VPPApi:
         return True
 
     def readconfig(self):
+        """Read the configuration out of a running VPP Dataplane and put it into a
+        VPP config cache"""
         # pylint: disable=no-member
         if not self.connected and not self.connect():
             self.logger.error("Could not connect to VPP")
@@ -257,6 +279,7 @@ class VPPApi:
         return ret
 
     def get_sub_interfaces(self):
+        """Return all interfaces which have a sub-id and one or more tags"""
         subints = [
             self.cache["interfaces"][x].interface_name
             for x in self.cache["interfaces"]
@@ -266,6 +289,7 @@ class VPPApi:
         return subints
 
     def get_qinx_interfaces(self):
+        """Return all interfaces which have a sub-id and a non-zero inner vlan tag"""
         qinx_subints = [
             self.cache["interfaces"][x].interface_name
             for x in self.cache["interfaces"]
@@ -275,6 +299,7 @@ class VPPApi:
         return qinx_subints
 
     def get_dot1x_interfaces(self):
+        """Return all interfaces which have only an outer vlan tag (dot1q/dot1ad)"""
         dot1x_subints = [
             self.cache["interfaces"][x].interface_name
             for x in self.cache["interfaces"]
@@ -284,6 +309,7 @@ class VPPApi:
         return dot1x_subints
 
     def get_loopbacks(self):
+        """Return all interfaces of VPP type 'Loopback'"""
         loopbacks = [
             self.cache["interfaces"][x].interface_name
             for x in self.cache["interfaces"]
@@ -292,6 +318,8 @@ class VPPApi:
         return loopbacks
 
     def get_phys(self):
+        """Return all interfaces for which the super interface has the same sw_if_index
+        and aren't known to be virtual interfaces"""
         phys = [
             self.cache["interfaces"][x].interface_name
             for x in self.cache["interfaces"]
@@ -303,6 +331,7 @@ class VPPApi:
         return phys
 
     def get_bondethernets(self):
+        """Return all bondethernet interfaces"""
         bonds = [
             self.cache["bondethernets"][x].interface_name
             for x in self.cache["bondethernets"]
@@ -310,6 +339,7 @@ class VPPApi:
         return bonds
 
     def get_vxlan_tunnels(self):
+        """Return all vxlan_tunnel interfaces"""
         vxlan_tunnels = [
             self.cache["interfaces"][x].interface_name
             for x in self.cache["interfaces"]
@@ -318,6 +348,7 @@ class VPPApi:
         return vxlan_tunnels
 
     def get_lcp_by_interface(self, sw_if_index):
+        """Return the LCP config cache for the interface given by sw_if_index"""
         for _idx, lcp in self.cache["lcps"].items():
             if lcp.phy_sw_if_index == sw_if_index:
                 return lcp
diff --git a/vppcfg b/vppcfg
index 16bbc95..479d411 100755
--- a/vppcfg
+++ b/vppcfg
@@ -30,6 +30,7 @@ except ImportError:
 
 
 def main():
+    """ The main vppcfg program """
     parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter)
     parser.add_argument(
         "-d",
@@ -175,7 +176,7 @@ def main():
         sys.exit(0)
 
     reconciler = Reconciler(cfg)
-    if not reconciler.vpp_readconfig():
+    if not reconciler.vpp.readconfig():
         sys.exit(-3)
 
     if not reconciler.phys_exist_in_vpp():