chore: improved knowledge about wake on lan

knowledge base/tcpdump.md

@@ -49,6 +49,9 @@ tcpdump -r 'path/to/capture.file'
 
 # Isolate TCP flags.
 tcpdump 'tcp[tcpflags] == tcp-fin'
+
+# Capture and show Wake-on-Lan magic packets.
+sudo tcpdump -nXxei any ether proto 0x0842 or udp port 9
 ```
 
 ## Sources

knowledge base/wake a host from lan.md

@@ -12,6 +12,11 @@ The host needs to support wake-on-LAN and have it enabled.
 
 See [`wakeonlan`][wakeonlan] or [`wol`][wol].
 
+```sh
+# Check the magic packet arrives on the target machine.
+sudo tcpdump -nXxei any ether proto 0x0842 or udp port 9
+```
+
 ## Further readings
 
 - [`wakeonlan`][wakeonlan]

knowledge base/wakeonlan.md

@@ -12,15 +12,15 @@
 # Install `wakeonlan`.
 brew install 'wakeonlan'
 
-# Send a WOL package to the host.
+# Broadcast a WOL package.
 wakeonlan '11:22:33:44:55:66'
 
-# Simulate.
+# Simulate the broadcast.
 wakeonlan -n '11:22:33:44:55:66'
 
-# Limit the magic package to a specific network or host.
+# Limit the magic package to specific networks or hosts.
-# Use a network's *broadcast* address unless you have a static ARP table
+# Use network *broadcast* addresses to ensure the magic packets can actually
-# configured so the magic packet can actually reach the single host.
+# reach the target host; avoid this by having a static ARP table configured.
 wakeonlan -i '192.168.1.255' '11:22:33:44:55:66'
 wakeonlan -n '11:22:33:44:55:66' -i '192.168.100.3'
 ```