Merge pull request #17241 from thezackm/chore/add-negate-operator

chore: add notes on creating negative lookahead

src/content/docs/network-performance-monitoring/advanced/advanced-config.mdx

@@ -2258,6 +2258,24 @@ The default behavior of this map is an `OR` condition, but you can override this
           "!if_Alias": "^Uplink.*"
     ```
   </Collapser>
+
+  <Collapser
+    id="negate-lookup"
+    title="Create a negative lookahead"
+  >
+    Golang's regex package does not support negative lookahead patterns (`q(?!u)`) by default. As a workaround, you can add the `DOES_NOT_MATCH` token to your attribute map to effectively give you the inverse results of your matching pattern.
+
+    For example, to match on every interface that **does not** include the string `Uplink`; you can use a configuration like this:
+
+    ```yaml
+    devices:
+      deviceName:
+        ...
+        match_attributes:
+          "!if_Alias": "^Uplink.*"
+          DOES_NOT_MATCH: true
+    ```
+  </Collapser>
 </CollapserGroup>
 
 ## The `response_time` and `ping_only` attributes [#response_time-attribute]