Clarify the reasoning for not installing a blackhole route for a PD.

diff --git a/dhcp6.c b/dhcp6.c
index f93071f6b51f7d60398de00e7ef34151478e8444..4b977867b273dafc1e27a5a045d2ca6f269d6822 100644 (file)
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -2387,7 +2387,10 @@ dhcp6_ifdelegateaddr(struct interface *ifp, struct ipv6_addr *prefix,
        a->prefix_len = (uint8_t)pfxlen;
 
        /* If sla is zero and the prefix length hasn't changed,
-        * don't install a blackhole route. */
+        * don't install a blackhole route.
+        * This does violate RFC3315 section 12.1, but technically
+        * the end result is no different from assigning the entire
+        * delegation so I'm OK with it. */
        if (sla->sla_set && sla->sla == 0 && prefix->prefix_len == pfxlen)
                prefix->flags |= IPV6_AF_DELEGATEDZERO;