diff --git a/net/icmpv6/icmpv6_input.c b/net/icmpv6/icmpv6_input.c
index f6e30008bde..1e5cdca30a4 100644
--- a/net/icmpv6/icmpv6_input.c
+++ b/net/icmpv6/icmpv6_input.c
@@ -238,7 +238,7 @@ void icmpv6_input(FAR struct net_driver_s *dev)
          */
 
         adv = ICMPv6RADVERTISE;
-        for (ndx = 0; ndx + sizeof(struct icmpv6_prefixinfo_s) < optlen; )
+        for (ndx = 0; ndx + sizeof(struct icmpv6_prefixinfo_s) <= optlen; )
           {
             FAR struct icmpv6_prefixinfo_s *opt =
               (FAR struct icmpv6_prefixinfo_s *)&adv->options[ndx];
@@ -313,7 +313,7 @@ void icmpv6_input(FAR struct net_driver_s *dev)
 
     default:
       {
-        nlldbg("Unknown ICMPv6 cmd: %d\n", icmp->type);
+        nlldbg("Unknown ICMPv6 type: %d\n", icmp->type);
         goto icmpv6_type_error;
       }
     }
diff --git a/net/icmpv6/icmpv6_rnotify.c b/net/icmpv6/icmpv6_rnotify.c
index 66d3370da1c..d2249d95fc9 100644
--- a/net/icmpv6/icmpv6_rnotify.c
+++ b/net/icmpv6/icmpv6_rnotify.c
@@ -152,8 +152,8 @@ static void icmpv6_setaddresses(FAR struct net_driver_s *dev,
 
   for (i = 0; i < 7; i++)
     {
-      dev->d_ipv6addr[i] = (dev->d_ipv6addr[i] & dev->d_ipv6netmask[i]) |
-                           (prefix[i] & ~dev->d_ipv6netmask[i]);
+      dev->d_ipv6addr[i] = (dev->d_ipv6addr[i] & ~dev->d_ipv6netmask[i]) |
+                           (prefix[i] & dev->d_ipv6netmask[i]);
     }
 
   nvdbg("prefix=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",