diff --git a/scripts/support/runner/core.py b/scripts/support/runner/core.py
index e451d76..ddf4d60 100644
--- a/scripts/support/runner/core.py
+++ b/scripts/support/runner/core.py
@@ -70,6 +70,73 @@
     return fmt.format(*args)
 
 
+MAX_PORT = 49151
+
+
+class NetworkPortHelper:
+    '''Helper class for dealing with local IP network ports.'''
+
+    def get_unused_ports(self, starting_from):
+        '''Find unused network ports, starting at given values.
+
+        starting_from is an iterable of ports the caller would like to use.
+
+        The return value is an iterable of ports, in the same order, using
+        the given values if they were unused, or the next sequentially
+        available unused port otherwise.
+
+        Ports may be bound between this call's check and actual usage, so
+        callers still need to handle errors involving returned ports.'''
+        start = list(starting_from)
+        used = self._used_now()
+        ret = []
+
+        for desired in start:
+            port = desired
+            while port in used:
+                port += 1
+                if port > MAX_PORT:
+                    msg = "ports above {} are in use"
+                    raise ValueError(msg.format(desired))
+            used.add(port)
+            ret.append(port)
+
+        return ret
+
+    def _used_now(self):
+        handlers = {
+            'Windows': self._used_now_windows,
+            'Linux': self._used_now_linux,
+            'Darwin': self._used_now_darwin,
+        }
+        handler = handlers[platform.system()]
+        return handler()
+
+    def _used_now_windows(self):
+        cmd = ['netstat', '-a', '-n', '-p', 'tcp']
+        return self._parser_windows(cmd)
+
+    def _used_now_linux(self):
+        cmd = ['netstat', '-a', '-n', '-t']
+        return self._parser_linux_darwin(cmd)
+
+    def _used_now_darwin(self):
+        cmd = ['netstat', '-a', '-n', '-p', 'tcp']
+        return self._parser_linux_darwin(cmd)
+
+    def _parser_windows(self, cmd):
+        out = subprocess.check_output(cmd).split(b'\r\n')
+        used_bytes = [x.split()[1].rsplit(b':', 1)[1] for x in out
+                      if x.startswith(b'  TCP')]
+        return {int(b) for b in used_bytes}
+
+    def _parser_linux_darwin(self, cmd):
+        out = subprocess.check_output(cmd).split(b'\n')
+        used_bytes = [x.split()[3].rsplit(b':', 1)[1] for x in out
+                      if x.startswith(b'tcp')]
+        return {int(b) for b in used_bytes}
+
+
 class ZephyrBinaryRunner(abc.ABC):
     '''Abstract superclass for binary runners (flashers, debuggers).