diff --git a/net/modemmanager/README.md b/net/modemmanager/README.md
index 0fa07a96c..ea86568c9 100644
--- a/net/modemmanager/README.md
+++ b/net/modemmanager/README.md
@@ -4,19 +4,33 @@
 
 Cellular modem control and connectivity
 
-Optional libraries libmbim and libqmi are available.  Optional mbim-utils and qmi-utils are available.
-Your modem may require additional kernel modules.
+Optional libraries libmbim and libqmi are available.
+Your modem may require additional kernel modules and/or the usb-modeswitch
+package.
 
 ## Usage
 
-# Once installed, you can configure the 2G/3G/4G modem connections directly in
-   /etc/config/network as in the following example:
+Once installed, you can configure the 2G/3G/4G modem connections directly in
+/etc/config/network as in the following example:
 
     config interface 'broadband'
-        option device   '/sys/devices/platform/soc/20980000.usb/usb1/1-1/1-1.2/1-1.2.1'
-        option proto    'modemmanager'
-        option apn      'ac.vodafone.es'
-        option username 'vodafone'
-        option password 'vodafone'
-        option pincode  '7423'
-        option lowpower '1'
+        option device      '/sys/devices/platform/soc/20980000.usb/usb1/1-1/1-1.2/1-1.2.1'
+        option proto       'modemmanager'
+        option apn         'ac.vodafone.es'
+        option allowedauth 'pap chap'
+        option username    'vodafone'
+        option password    'vodafone'
+        option pincode     '7423'
+        option iptype      'ipv4'
+        option lowpower    '1'
+
+Only 'device' and 'proto' are mandatory options, the remaining ones are all
+optional.
+
+The 'allowedauth' option allows limiting the list of authentication protocols.
+It is given as a space-separated list of values, including any of the
+following: 'pap', 'chap', 'mschap', 'mschapv2' or 'eap'. It will default to
+allowing all protocols.
+
+The 'iptype' option supports any of these values: 'ipv4', 'ipv6' or 'ipv4v6'.
+It will default to 'ipv4' if not given.
diff --git a/net/modemmanager/files/modemmanager.proto b/net/modemmanager/files/modemmanager.proto
index be1bcb3df..2e95d1e57 100755
--- a/net/modemmanager/files/modemmanager.proto
+++ b/net/modemmanager/files/modemmanager.proto
@@ -116,6 +116,35 @@ modemmanager_connected_method_ppp_ipv4() {
 	local ttyname="$2"
 	local username="$3"
 	local password="$4"
+	local allowedauth="$5"
+
+	# all auth types are allowed unless a user given list is given
+	local authopts
+	local pap=1
+	local chap=1
+	local mschap=1
+	local mschapv2=1
+	local eap=1
+
+	[ -n "$allowedauth" ] && {
+		pap=0 chap=0 mschap=0 mschapv2=0 eap=0
+		for auth in $allowedauth; do
+			case $auth in
+				"pap") pap=1 ;;
+				"chap") chap=1 ;;
+				"mschap") mschap=1 ;;
+				"mschapv2") mschapv2=1 ;;
+				"eap") eap=1 ;;
+				*) ;;
+			esac
+		done
+	}
+
+	[ $pap -eq 1 ] || append authopts "refuse-pap"
+	[ $chap -eq 1 ] || append authopts "refuse-chap"
+	[ $mschap -eq 1 ] || append authopts "refuse-mschap"
+	[ $mschapv2 -eq 1 ] || append authopts "refuse-mschap-v2"
+	[ $eap -eq 1 ] || append authopts "refuse-eap"
 
 	proto_run_command "${interface}" /usr/sbin/pppd \
 		"${ttyname}" \
@@ -126,6 +155,7 @@ modemmanager_connected_method_ppp_ipv4() {
 		nopcomp \
 		novj \
 		noauth \
+		$authopts \
 		${username:+ user $username} \
 		${password:+ password $password} \
 		lcp-echo-failure 5 \
@@ -307,6 +337,7 @@ proto_modemmanager_init_config() {
 	no_device=1
 	proto_config_add_string	 device
 	proto_config_add_string	 apn
+	proto_config_add_string	 'allowedauth:list(string)'
 	proto_config_add_string	 username
 	proto_config_add_string	 password
 	proto_config_add_string	 pincode
@@ -319,14 +350,14 @@ proto_modemmanager_setup() {
 	local interface="$1"
 
 	local modempath modemstatus bearercount bearerpath connectargs bearerstatus beareriface
-	local bearermethod_ipv4 bearermethod_ipv6
+	local bearermethod_ipv4 bearermethod_ipv6 auth cliauth
 	local operatorname operatorid registration accesstech signalquality
 
-	local device apn username password pincode iptype metric
+	local device apn allowedauth username password pincode iptype metric
 
 	local address prefix gateway mtu dns1 dns2
 
-	json_get_vars device apn username password pincode iptype metric
+	json_get_vars device apn allowedauth username password pincode iptype metric
 
 	# validate sysfs path given in config
 	[ -n "${device}" ] || {
@@ -355,9 +386,14 @@ proto_modemmanager_setup() {
 	# always cleanup before attempting a new connection, just in case
 	modemmanager_cleanup_connection "${modemstatus}"
 
+	# if allowedauth list given, build option string
+	for auth in $allowedauth; do
+		cliauth="${cliauth}${cliauth:+|}$auth"
+	done
+
 	# setup connect args; APN mandatory (even if it may be empty)
 	echo "starting connection with apn '${apn}'..."
-	connectargs="apn=${apn}${iptype:+,ip-type=${iptype}}${username:+,user=${username}}${password:+,password=${password}}${pincode:+,pin=${pincode}}"
+	connectargs="apn=${apn}${iptype:+,ip-type=${iptype}}${cliauth:+,allowed-auth=${cliauth}}${username:+,user=${username}}${password:+,password=${password}}${pincode:+,pin=${pincode}}"
 	mmcli --modem="${device}" --timeout 120 --simple-connect="${connectargs}" || {
 		proto_notify_error "${interface}" CONNECT_FAILED
 		proto_block_restart "${interface}"
@@ -411,7 +447,7 @@ proto_modemmanager_setup() {
 			modemmanager_connected_method_static_ipv4 "${interface}" "${beareriface}" "${address}" "${prefix}" "${gateway}" "${mtu}" "${dns1}" "${dns2}" "${metric}"
 			;;
 		"ppp")
-			modemmanager_connected_method_ppp_ipv4 "${interface}" "${beareriface}" "${username}" "${password}"
+			modemmanager_connected_method_ppp_ipv4 "${interface}" "${beareriface}" "${username}" "${password}" "${allowedauth}"
 			;;
 		*)
 			proto_notify_error "${interface}" UNKNOWN_METHOD