diff --git a/src/test/shell/bazel/remote_helpers.sh b/src/test/shell/bazel/remote_helpers.sh
index 7301d87..ef80a74 100755
--- a/src/test/shell/bazel/remote_helpers.sh
+++ b/src/test/shell/bazel/remote_helpers.sh
@@ -119,32 +119,41 @@
 #   * redirect_log - the path to nc's log.
 #   * redirect_pid - the PID of nc.
 function serve_redirect() {
-  # Assign random_port to nc_port if not already set.
-  echo ${redirect_port:=$(pick_random_unused_tcp_port)} > /dev/null
-  redirect_log=$TEST_TMPDIR/redirect.log
-  local response=$(cat <<EOF
-HTTP/1.0 301 Moved Permanently
-Location: $1
-
-EOF
-)
-  nc_l $redirect_port >& $redirect_log <<<"$response" &
+  redirect_log="${TEST_TMPDIR}/redirect.log"
+  rm -f $redirect_log
+  touch $redirect_log
+  cd "${TEST_TMPDIR}"
+  port_file=server-port.$$
+  # While we "own" the port_file for the life time of this process, there can
+  # be a left-over file from a previous process that had the process id (there
+  # are not that many possible process ids after all) or even the same process
+  # having started and shut down a server for a different test case in the same
+  # shard. So we have to remove any left-over file in order to not exit the
+  # while loop below too early because of finding the string "started" in the
+  # old file (and thus potentially even getting an outdated port information).
+  rm -f $port_file
+  python $python_server redirect $1 > $port_file &
   redirect_pid=$!
+  while ! grep started $port_file; do sleep 1; done
+  redirect_port=$(head -n 1 $port_file)
+  fileserver_port=$redirect_port
+  wait_for_server_startup
+  cd -
 }
 
 # Serves a HTTP 404 Not Found response with an optional parameter for the
 # response body.
 function serve_not_found() {
-  RESPONSE_BODY=${1:-}
-  http_response=$TEST_TMPDIR/http_response
-  cat > $http_response <<EOF
-HTTP/1.0 404 Not Found
-
-$RESPONSE_BODY
-EOF
-  nc_port=$(pick_random_unused_tcp_port) || exit 1
-  nc_l $nc_port < $http_response &
+  port_file=server-port.$$
+  cd "${TEST_TMPDIR}"
+  rm -f $port_file
+  python $python_server 404 > $port_file &
   nc_pid=$!
+  while ! grep started $port_file; do sleep 1; done
+  nc_port=$(head -n 1 $port_file)
+  fileserver_port=$nc_port
+  wait_for_server_startup
+  cd -
 }
 
 # Waits for the SimpleHTTPServer to actually start up before the test is run.
diff --git a/src/test/shell/bazel/testing_server.py b/src/test/shell/bazel/testing_server.py
index bf869b3..7ba93a6 100644
--- a/src/test/shell/bazel/testing_server.py
+++ b/src/test/shell/bazel/testing_server.py
@@ -36,7 +36,9 @@
 class Handler(BaseHTTPRequestHandler):
   """Handlers for testing HTTP server."""
   auth = False
+  not_found = False
   filename = None
+  redirect = None
   valid_header = b'Basic ' + base64.b64encode('foo:bar'.encode('ascii'))
 
   def do_HEAD(self):  # pylint: disable=invalid-name
@@ -51,6 +53,17 @@
     self.end_headers()
 
   def do_GET(self):  # pylint: disable=invalid-name
+    if self.not_found:
+      self.send_response(404)
+      self.end_headers()
+      return
+
+    if self.redirect is not None:
+      self.send_response(301)
+      self.send_header('Location', self.redirect)
+      self.end_headers()
+      return
+
     if not self.auth:
       self.do_HEAD()
       self.serve_file()
@@ -79,6 +92,10 @@
 
   if len(argv) > 1 and argv[0] == 'always':
     Handler.filename = argv[1]
+  elif len(argv) > 1 and argv[0] == 'redirect':
+    Handler.redirect = argv[1]
+  elif argv and argv[0] == '404':
+    Handler.not_found = True
   elif argv:
     Handler.auth = True