doc/fields_snmp: complete the example with details

doc/16-Fields-example-SNMP.md

@@ -15,6 +15,7 @@ Your services should now be applied not only based on various Host properties
 like `Device Type`, `Application`, `Customer` or similar - but also based on
 the fact whether credentials have been given or not.
 
+
 Prepare required Data Fields
 ----------------------------
 
@@ -37,7 +38,7 @@ a `Data Field` using that list:
 
 Next, please also create the following elements:
 
-* a list *SNMPv3 Auth Types* providing `MD5` and `AES`
+* a list *SNMPv3 Auth Types* providing `MD5` and `SHA`
 * a list *SNMPv3 Priv Types* providing at least `AES` and `DES`
 * a `String` type field `snmp_community` labelled *SNMP Community*
 * a `String` type field `snmpv3_user` labelled *SNMPv3 User*
@@ -49,3 +50,55 @@ Next, please also create the following elements:
 Please do not forget to add meaningful descriptions, telling your users about
 in-house best practices.
 
+
+Assign your shiny new Fields to a Template
+------------------------------------------
+
+I'm using my default Host Template for this, but one might also choose to provide
+`SNMP version` on Network Devices. Should Network Device be a template? Or just
+an option in a `Device Type` field? You see, the possibilities are endless here.
+
+This screenshot shows part of my assigned Fields:
+
+![SNMP Fields on Default Host](screenshot/director/16_fields_snmp/164_snmp_fields_on_template.png)
+
+While I kept `SNMP Version` optional, all other fields are mandatory.
+
+
+Use your Template
+-----------------
+
+As soon as you choose your template, a new field is shown:
+
+![Choose SNMP version](screenshot/director/16_fields_snmp/165_host_snmp_choose.png)
+
+In case you change it to `SNMPv2c`, a `Community String` will be required:
+
+![Community String for SNMPv2c](screenshot/director/16_fields_snmp/166_host_snmp_v2c.png)
+
+Switch it to SNMPv3 to see completely different fields:
+
+![Auth and Priv properties for SNMPv3](screenshot/director/16_fields_snmp/167_host_snmp_v3.png)
+
+Once stored please check the rendered configuration. Switch the SNMP versions
+forth and back, and you should see that filtered fields will also remove the
+corresponding values from the object.
+
+
+Assign Services based on those properties
+-----------------------------------------
+
+You should design your Commands to use that set of properties. Change the example
+slightly to fit ITL Commands in case you're using those (snmpv3_*_type VS _alg).
+
+Your Cisco Health checks assigned to all:
+
+* routers or switches
+* manifactured by Cisco
+* with SNMP credentials, regardless of which version
+
+...might then look as follows:
+
+![Assign SNMP-based checks](screenshot/director/16_fields_snmp/168_assign_snmp_check.png)
+
+Have fun!