Update comment to explain absence of adjustment to g-bit.

diff --git a/server/mdb6.c b/server/mdb6.c
index a5ae4eb739a82539a11d1391deedc64cf982e7b3..73b7fdfa8c9449902f7fa4a344a3befcbabd126a 100644 (file)
--- a/server/mdb6.c
+++ b/server/mdb6.c
@@ -636,7 +636,12 @@ build_address6(struct in6_addr *addr,
                case 6: str[i] = (str[i] & 0x03) | (net_str[i] & 0xFC); break;
                case 7: str[i] = (str[i] & 0x01) | (net_str[i] & 0xFE); break;
        }
-       /* set the 'u' bit to zero for /64s. */
+
+       /*
+        * Set the universal/local bit ("u bit") to zero for /64s.  The
+        * individual/group bit ("g bit") is unchanged, because the g-bit
+        * has no meaning when the u-bit is cleared.
+        */
        if (net_bits == 64)
                str[8] &= ~0x02;
 }