Extensively clarify "Identify IP address" section.

WSL/basic-commands.md

@@ -168,8 +168,44 @@ To terminate the specified distribution, or stop it from running, replace `<Dist
 
 ## Identify IP address
 
-- `wsl hostname -i` for the IP address of your Linux distribution installed via WSL 2 (the WSL 2 VM address)
-- `cat /etc/resolv.conf` for the IP address of the Windows machine as seen from WSL 2 (the WSL 2 VM)
+There are two scenarios involved.
+
+Scenario One: From the perspective of the Windows host, you want to query a WSL2 distribution's IP address, so that a program on Windows host can connect to a server program running inside the WSL distribution(instance). 
+
+The Windows host can use command:
+
+```
+wsl -d <DistributionName> hostname -I
+```
+
+If we are querying the default distribution, we can omit `-d <DistributionName>` option.
+
+Under the hood, host command `wsl.exe` launches the target instance right away, and tells it to execute Linux command `hostname -I` (which prints WSL instance's own IP to STDOUT) then the STDOUT text content is relayed back to wsl.exe, and finally wsl.exe prints that out to us. 
+
+
+A typical output can be:
+
+```
+172.30.98.229
+```
+
+Scenario Two: A program running inside WSL2 instance wants to know the Windows host's IP address, so that a Linux program can connect to a Windows host server program. 
+
+The WSL2 Linux user can use command `cat /etc/resolv.conf`, which outputs something like:
+
+```
+# This file was automatically generated by WSL. To stop automatic generation of this file, add the following entry to /etc/wsl.conf:
+# [network]
+# generateResolvConf = false
+nameserver 172.30.96.1
+```
+
+So the `172.30.96.1` is the Window host's IP address, in this example.
+
+> [!NOTE]
+> These above IP address querying action is typically required when WSL2 is running with [NAT network mode](./networking.md#default-networking-mode-nat). 
+> When the WSL2 is running with new [mirrored mode](./networking.md#mirrored-mode-networking), the Windows host and WSL2 VM can connect to each other using `localhost` (127.0.0.1) as destination address, so the trick of query peer's IP address is not required.
+
 
 ## Export a distribution