diff --git a/Dockerfile b/Dockerfile
index b86f000..a719ae0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -58,6 +58,7 @@ COPY docker/settings.py /opt/layerindex/settings.py
 COPY docker/refreshlayers.sh /opt/refreshlayers.sh
 COPY docker/updatelayers.sh /opt/updatelayers.sh
 COPY docker/migrate.sh /opt/migrate.sh
+COPY docker/connectivity_check.sh /opt/connectivity_check.sh
 
 RUN mkdir /opt/workdir \
 	&& adduser --system --uid=500 layers \
diff --git a/docker/connectivity_check.sh b/docker/connectivity_check.sh
new file mode 100755
index 0000000..59b26b8
--- /dev/null
+++ b/docker/connectivity_check.sh
@@ -0,0 +1,35 @@
+#!/bin/sh
+
+# Run a few connectivity checks
+echo "Checking external connectivity..."
+
+CCTEMP=`mktemp -d`
+cd $CCTEMP || exit 1
+
+cleanup_tmp() {
+    cd /tmp
+    rm -rf $CCTEMP
+}
+
+HTTP_TEST_URL="http://example.com"
+if ! wget -q $HTTP_TEST_URL ; then
+    echo "ERROR: failed to fetch $HTTP_TEST_URL"
+    cleanup_tmp
+    exit 1
+fi
+
+HTTPS_TEST_URL="https://google.com"
+if ! wget -q $HTTPS_TEST_URL ; then
+    echo "ERROR: failed to fetch $HTTPS_TEST_URL"
+    cleanup_tmp
+    exit 1
+fi
+
+GIT_TEST_REPO="git://git.yoctoproject.org/meta-layerindex-test"
+if ! git clone -q $GIT_TEST_REPO ; then
+    echo "ERROR: failed to clone $GIT_TEST_REPO"
+    cleanup_tmp
+    exit 1
+fi
+
+cleanup_tmp
diff --git a/dockersetup.py b/dockersetup.py
index 37f3f17..299d3f9 100755
--- a/dockersetup.py
+++ b/dockersetup.py
@@ -56,6 +56,7 @@ def get_args():
     parser.add_argument('--letsencrypt', action="store_true", default=False, help='Use Let\'s Encrypt for HTTPS')
     parser.add_argument('--no-migrate', action="store_true", default=False, help='Skip running database migrations')
     parser.add_argument('--no-admin-user', action="store_true", default=False, help='Skip adding admin user')
+    parser.add_argument('--no-connectivity', action="store_true", default=False, help='Skip checking external network connectivity')
 
     args = parser.parse_args()
 
@@ -488,6 +489,13 @@ def edit_options_file(project_name):
         f.write('project_name=%s\n' % project_name)
 
 
+def check_connectivity():
+    return_code = subprocess.call(['docker-compose', 'run', '--rm', 'layersapp', '/opt/connectivity_check.sh'], shell=False)
+    if return_code != 0:
+        print("Connectivity check failed - if you are behind a proxy, please check that you have correctly specified the proxy settings on the command line (see --help for details)")
+        sys.exit(1)
+
+
 def generatepasswords(passwordlength):
     return ''.join([random.SystemRandom().choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@%^&*-_+') for i in range(passwordlength)])
 
@@ -648,6 +656,10 @@ if return_code != 0:
     print("docker-compose up failed")
     sys.exit(1)
 
+if not (args.update or args.no_connectivity):
+    ## Run connectivity check
+    check_connectivity()
+
 # Get real project name (if only there were a reasonable way to do this... ugh)
 real_project_name = ''
 output = subprocess.check_output(['docker-compose', 'ps', '-q'], shell=False)