Add supported protocols to README

---

+ Add example page for dnp3linkaddr

Author: MatrixEditor

README.md

@@ -1,6 +1,19 @@
 # icspacket
 
-*Content will be added soon enough...*
+A collection of Python classes and tools to interact with industrial control
+systems using their protocols. Currently supported protocols are:
+
+```
+- DNP3.0 (IEEE 1815)
+- MMS (ISO 9506) and mappings for IEC 61850
+- ACSE (X.227)
+- COPP (X.226)
+- COSP (X.225)
+- COTP (X.224)
+- TPKT (RFC1006)
+```
+
+**Please review the documentation for more information and tools: [icspacket-docs](https://matrixeditor.github.io/icspacket/)**
 
 **CI Status**
 

docs/source/index.rst

@@ -7,7 +7,8 @@ icspacket
 
 .. rst-class:: lead
 
-    *Contents of this side are WIP*
+    *A collection of Python classes and tools to interact with industrial control
+    systems using their protocols.*
 
 .. container:: buttons
 
@@ -18,6 +19,8 @@ icspacket
 
 
 
+*Contents of this side are WIP*
+
 
 Getting Started
 ---------------
@@ -42,6 +45,7 @@ and MacOS. Any other Python version is not officially supported::
 
     protocols/dnp3/dnp3read
     protocols/dnp3/dnp3dump
+    protocols/dnp3/dnp3resolve
     protocols/dnp3/api
 
 .. toctree::

docs/source/protocols/dnp3/dnp3resolve.rst

@@ -0,0 +1,67 @@
+.. _dnp3resolve:
+
+Resolve Link Addresses
+======================
+
+Overview
+--------
+
+The ``dnp3linkaddr`` tool is designed to **discover the link address of a DNP3 outstation**.
+Since many DNP3 deployments require knowledge of the correct remote link address
+before initiating communication, this tool provides automated resolution methods
+instead of relying on brute force.
+
+The tool currently uses two approaches:
+
+1. **Self-Address Method**
+   Send a ``REQUEST_LINK_STATUS`` message using the *Self* address (``0xFFFE``).
+   If the outstation supports this optional feature, it will reply with its configured link address.
+
+2. **Passive Listening Method**
+   Listen for ``REQUEST_LINK_STATUS`` messages periodically sent by the
+   outstation (as required by `DNP3 specification section 9.2.6.5`).
+   This allows link address resolution without requiring the *Self* address feature.
+
+.. note::
+
+   Some outstations poll at different intervals — typically between **5 and 60 seconds**.
+   You may need to wait for up to a full cycle before receiving a ``REQUEST_LINK_STATUS`` frame.
+   Be patient, especially when relying solely on the passive listening method.
+
+
+Usage
+-----
+
+**Resolve using the Self-Address method (default):**
+
+.. code-block:: bash
+
+   dnp3linkaddr 127.0.0.1
+
+This will attempt to send a ``REQUEST_LINK_STATUS`` message using the *Self*
+address. If the outstation supports it, the tool will display the resolved link
+address.
+
+**Resolve by waiting for a periodic status request:**
+
+.. code-block:: bash
+
+   dnp3linkaddr 127.0.0.1 -no-self -interval 45
+
+This disables the *Self* method and waits up to 45 seconds for the outstation to
+send a ``REQUEST_LINK_STATUS`` message.
+
+
+Practical Notes
+---------------
+
+- The **Self-Address method** is not mandatory in DNP3 and may not be implemented by all outstations.
+- The **passive listening method** is more reliable but depends on the polling cycle of the outstation.
+- Always verify that the **local link address** (``--listen``) matches what the
+  outstation expects from the master.
+
+.. hint::
+
+    - Ain't nobody got no time for that - but patience is key here: some
+      devices only send ``REQUEST_LINK_STATUS`` messages once every 60 seconds.
+