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HOWTO.md

+# HOWTO
+
+1. Requirements 
+
+    You need at least CMK 2.2.0 or CMK 2.3.0 to use the Network visualization
+
+1. installed packages
+
+    For the Network visualization to work you need to install some additional plugins (MKPs). 
+    
+    For the OSI layer 2 topology
+    - [CDP cache HW/SW inventory plugin](https://thl-cmk.hopto.org/gitlab/checkmk/vendor-independent/inventory/inv_cdp_cache)
+    - [LLDP cache HW/SW inventory plugin](https://thl-cmk.hopto.org/gitlab/checkmk/vendor-independent/inventory/inv_lldp_cache)
+
+    For the OSI layer 3 topology
+    - [IPv4 address HW/SW inventory plugin](https://thl-cmk.hopto.org/gitlab/checkmk/vendor-independent/inventory/inv_ipv4_addresses)
+
+    For the name to service matching (optional, but recommended)
+    - [INV_IFNAME HW/SW inventory plugin](https://thl-cmk.hopto.org/gitlab/checkmk/vendor-independent/inventory/inv_ifname)
+
+    For the topology data creation
+    - [NVDCT (NetworkVisualizationDataCreationTool) plugin](https://thl-cmk.hopto.org/gitlab/checkmk/vendor-independent/nvdct)
+
+    For topology visualization (only CMK 2.2.0x, CMK 2.3.0 has this built-in)
+    - [Network visualization plugin](https://exchange.checkmk.com/p/network-visualization)
+
+1. Rules
+
+    Enable the HW/SW inventory for all your (network) devices that you want to include in the topology.
+
+1. Host labels
+
+    Some parts of the NVDCT are dependent on the presence of certain host labels:
+    - `nvdct/routing_capable:yes` for the IPv4 topology and `--pre-fetch` option
+    - `nvdct/has_cdp_neighbours:yes` for the `--pre-fetch` option
+    - `nvdct/has_lldp_neighbours:yes` for the `--pre-fetch` option
+
+    After installing the HW/SW inventory plugins, you must therefore perform a new search for host labels (_**Bulk discovery**_ -> _**Only discover new host labels**_).
+
+
+
+1. Check the HW/SW inventory
+
+    Run the HW/SW inventory at least once for each host and then check whether the required data has been found. If so, proceed to the next step.
+
+1. Modify the user settings for NVDCT
+
+    Before you create the topology data, take a look at _**nvdct.toml**_. Here you can fine tune some aspects of the topology creation. If you want/need to do this, please create a copy of the nvdct.toml file (e.g. my_nvdct.toml) and only change the copy. By not changing the nvdct.toml file, you ensure that your changes will survive the next update.
+
+1. Create the topology data
+
+```
+~/local/bin/nvdct/nvdct.py -u ~/local/bin/nvdct/my_nvdct.toml
+```
+
+1. Go to CMK and show the network topology