update historical note

python · picnixz · Jun 8, 2025 · Jun 6, 2025 · Jun 8, 2025 · Jun 8, 2025
commit c5249d4c405dd066889a634e0af5fe9bcae1771c
diff --git a/Lib/uuid.py b/Lib/uuid.py
@@ -656,10 +656,13 @@ def _windll_getnode():
 
 def _random_getnode():
     """Get a random node ID."""
-    # RFC 4122, $4.1.6 says "For systems with no IEEE address, a randomly or
-    # pseudo-randomly generated value may be used; see Section 4.5.  The
-    # multicast bit must be set in such addresses, in order that they will
-    # never conflict with addresses obtained from network cards."
+    # RFC 9562, §6.10 says that
+    #
+    #   Implementations MAY elect to obtain a 48-bit cryptographic-quality
+    #   random number as per Section 6.9 to use as the Node ID. [...] [and]
+    #   implementations MUST set the least significant bit of the first octet
+    #   of the Node ID to 1. This bit is the unicast or multicast bit, which
+    #   will never be set in IEEE 802 addresses obtained from network cards.
     #
     # The "multicast bit" of a MAC address is defined to be "the least
     # significant bit of the first octet".  This works out to be the 41st bit