remove is_rpi -> is_raspbian, more notes

roles/network/templates/hostapd/hostapd.service.j2

@@ -2,7 +2,7 @@
 Description=Hostapd IEEE 802.11 AP, IEEE 802.1X/WPA/WPA2/EAP/RADIUS Authenticator
 Wants=network-pre.target
 After=network-pre.target
-{% if is_rpi %}
+{% if is_raspbian %}
 Before=dhcpcd.service
 {% endif %}
 Before=network.target

roles/network/templates/network/dhcpcd.conf.j2

@@ -38,13 +38,18 @@ require dhcp_server_identifier
 slaac private
 
 # IIAB
+denyinterfaces ap0
 
+# Setting iiab_wired_lan_iface would install the device as a slave under
+# br0 so we need to turn off the dhcp client in that network layout.
+# Auto creation of the wired slave is suppressed in discovered_network.yml
+# -> Set iiab_wired_lan_iface if present is conditional on is_raspbian
+# Slave creation can be forced by populating local_vars.yml with
+# 'iiab_wired_lan_iface: eth0' which populates /etc/network/interfaces.d/iiab
+# with 'bridge_ports eth0' in place of 'bridge_ports none'
 # Always (try) to run DHCP client on RPi's Ethernet port, for in-field
 # "cablemodems" used by many non-technical operators, who want Zero-Hassle
 # Updates.  This means AVOIDING "denyinterfaces eth0" below:
-{% if is_rpi and hostapd_enabled %}
-denyinterfaces ap0
-{% endif %}
 {% if iiab_wired_lan_iface is defined %}
 denyinterfaces {{ iiab_wired_lan_iface }}
 {% endif %}

roles/network/templates/network/rpi.j2

@@ -3,6 +3,8 @@
 # gui_desired_network_role is {{ gui_desired_network_role }}
 {% endif %}
 {% if iiab_network_mode != "Appliance"  %}
+# auto wired slave creation is suppressed in detected_network.yml
+# 'none' would become the name of the wired slave device.
 #################   LANCONTROLLER   ###################
 auto br0
 iface br0 inet manual