fix IPv6 multicast

Author: spacemanspiff2007

.ruff.toml

@@ -30,9 +30,6 @@ ignore = [
     # https://docs.astral.sh/ruff/rules/#flake8-bandit-s
     "S311",     # Standard pseudo-random generators are not suitable for cryptographic purposes
 
-    # https://docs.astral.sh/ruff/rules/#pyupgrade-up
-    "UP038",    # Use X | Y in {} call instead of (X, Y)
-
     # https://docs.astral.sh/ruff/rules/#flake8-annotations-ann
     "ANN401",   # Dynamically typed expressions (typing.Any) are disallowed in {name}
 

src/pyartnet/impl_sacn/node.py

@@ -150,16 +150,13 @@ def _get_universe_ip_port(self, universe: int) -> tuple[str, int] | str:
 
         u = self._validate_universe_nr(universe)
 
-        universe_high = u // 255
-        universe_low = u % 255
-
         # IPv6 multicast address
         if ':' in self._ip:
             IPv6Address(self._ip)  # validate IP
-            return f'FF18::83:00:{universe_high:d}:{universe_low:d}'
+            return f'FF18::8300:{u:04X}'
 
         # IPv4 multicast address
-        return f'239.255.{universe_high:d}.{universe_low:d}'
+        return f'239.255.{u // 255:d}.{u % 255:d}'
 
     @override
     def set_multicast_mode(self, enabled: bool) -> Self: