diff --git a/.travis.yml b/.travis.yml
index b4d6d7df..e63f305e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,21 @@
-# Travis script for test-building this library.
+##############################################################################
+#
+# File: .travis.yml
+#
+# Function:
+#     Travis script for test-building this library.
+#
+# Copyright Notice:
+#     See LICENSE file accompanying this project.
+#
+# Author:
+#     Terry Moore, MCCI Corporation   April 2018
+#
+##############################################################################
+
 language: c
 dist: trusty
+sudo: true
 
 env:
  global:
@@ -34,9 +49,19 @@ before_install:
   - export ARDUINO_IDE=arduino_ide/${IDE_VERSION}
   - export ARDUINO_LIBS="$HOME/Arduino/libraries"
   - if [ ! -d "$HOME/arduino_ide" ] ; then mkdir "$HOME/arduino_ide" ; fi
-  - if [ ! -d "$HOME/$ARDUINO_IDE" ] ; then { echo "fetch" && wget http://downloads.arduino.cc/arduino-${IDE_VERSION}-linux64.tar.xz && echo "untar" && tar xf arduino-${IDE_VERSION}-linux64.tar.xz && echo "move" && mv -f arduino-${IDE_VERSION} $HOME/${ARDUINO_IDE} ; } || { echo "IDE install failed"; exit 1; } ; else echo "IDE already installed" ; fi
+  - if [ ! -d "$HOME/$ARDUINO_IDE" ] ; then { echo "fetch" && wget https://downloads.arduino.cc/arduino-${IDE_VERSION}-linux64.tar.xz && echo "untar" && tar xf arduino-${IDE_VERSION}-linux64.tar.xz && echo "move" && mv -f arduino-${IDE_VERSION} $HOME/${ARDUINO_IDE} ; } || { echo "IDE install failed"; exit 1; } ; else echo "IDE already installed" ; fi
   - ln -sf $PWD $HOME/${ARDUINO_IDE}/libraries/Test_Library
   - export PATH="$HOME/${ARDUINO_IDE}:$PATH"
+
+  # Arduino IDE adds a lot of noise caused by network traffic, trying to firewall it off
+  # (see https://github.com/per1234/arduino-ci-script/issues/1#issuecomment-504158113)
+  - sudo iptables -P INPUT DROP
+  - sudo iptables -P FORWARD DROP
+  - sudo iptables -P OUTPUT ACCEPT
+  - sudo iptables -A INPUT -i lo -j ACCEPT
+  - sudo iptables -A OUTPUT -o lo -j ACCEPT
+  - sudo iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
+
   #
   # functions to generate the board settings for SAMD, STM32L0, ...
   # keep args for these aligned for any common options. $1 is always board name, $2 is region.
diff --git a/ci/platformio.sh b/ci/platformio.sh
index e0cdfcd9..ce1718aa 100755
--- a/ci/platformio.sh
+++ b/ci/platformio.sh
@@ -1,5 +1,20 @@
 #!/bin/bash
 
+##############################################################################
+#
+# File: .travis.yml
+#
+# Function:
+#     Travis script for test-building this library.
+#
+# Copyright Notice:
+#     See LICENSE file accompanying this project.
+#
+# Author:
+#     Francesco Zardi   March 2019
+#
+##############################################################################
+
 # Treat unset variables and parameters as an error
 set -o nounset
 
@@ -14,11 +29,11 @@ set -o pipefail
 if [[ ! -v TARGET ]]
 then
     echo "ERROR: variable TARGET is not defined. Please run this scripts as shown next:"
-    echo "    TARGET='foo' $BASH_SOURCE"
-elif [ "$TARGET" == "avr" ]
+    echo "    TARGET='foo' ${BASH_SOURCE[*]}"
+elif [ "$TARGET" == "esp32" ]
 then
     ################################################################################
-    # TEST FOR TARGET "avr", i.e. BOARD heltec_wifi_lora_32
+    # TEST FOR TARGET "esp32", i.e. BOARD heltec_wifi_lora_32
 
     # Compile "ttn-otaa" example in all regions
     PLATFORMIO_BUILD_FLAGS='-D CFG_us915   -D CFG_sx1276_radio -D COMPILE_REGRESSION_TEST -D ARDUINO_LMIC_PROJECT_CONFIG_H_SUPPRESS' platformio ci --lib . --board heltec_wifi_lora_32 'examples/ttn-otaa/ttn-otaa.ino'
@@ -97,11 +112,11 @@ then
     # Expect failure when compiling for more than one radio
     if [ "$(PLATFORMIO_BUILD_FLAGS='-D CFG_sx1272_radio -D CFG_sx1276_radio' platformio ci --lib . --board heltec_wifi_lora_32 'examples/ttn-otaa/ttn-otaa.ino' 1>&2; echo $?)" -eq 0 ]; then echo "ERROR: Compilation did not fail!"; exit 1; fi
 
-elif [ "$TARGET" == "esp32" ]
+elif [ "$TARGET" == "avr" ]
 then
 
     ################################################################################
-    # TESTS FOR TARGET "esp32", i.e. BOARD feather32u4
+    # TESTS FOR TARGET "avr", i.e. BOARD feather32u4
 
     PLATFORMIO_BUILD_FLAGS='-D COMPILE_REGRESSION_TEST'                                                                              platformio ci --lib . --board feather32u4 'examples/ttn-otaa-feather-us915/ttn-otaa-feather-us915.ino'
     PLATFORMIO_BUILD_FLAGS='-D COMPILE_REGRESSION_TEST -D ARDUINO_LMIC_PROJECT_CONFIG_H_SUPPRESS -D CFG_au921   -D CFG_sx1276_radio' platformio ci --lib . --board feather32u4 'examples/ttn-otaa-feather-us915/ttn-otaa-feather-us915.ino'