diff --git a/bacnet-stack/bip.c b/bacnet-stack/bip.c
index c7c4ae0d..f1aea3dc 100644
--- a/bacnet-stack/bip.c
+++ b/bacnet-stack/bip.c
@@ -125,21 +125,23 @@ int bip_send_pdu(BACNET_ADDRESS * dest, /* destination address */
 
     mtu[0] = BVLL_TYPE_BACNET_IP;
     bip_dest.sin_family = AF_INET;
-    if (dest->mac_len == 6) {
+    if (dest->net == BACNET_BROADCAST_NETWORK) {
+        /* broadcast */
+        bip_dest.sin_addr.s_addr = htonl(BIP_Broadcast_Address.s_addr);
+        bip_dest.sin_port = htons(BIP_Port);
+        memset(&(bip_dest.sin_zero), '\0', 8);
+        mtu[1] = BVLC_ORIGINAL_BROADCAST_NPDU;
+    } else if (dest->mac_len == 6) {
+        /* valid unicast */
         (void) decode_unsigned32(&dest->mac[0],
             &(bip_dest.sin_addr.s_addr));
         (void) decode_unsigned16(&dest->mac[4], &(bip_dest.sin_port));
         memset(&(bip_dest.sin_zero), '\0', 8);
         mtu[1] = BVLC_ORIGINAL_UNICAST_NPDU;
-    }
-    /* broadcast */
-    else if (dest->mac_len == 0) {
-        bip_dest.sin_addr.s_addr = htonl(BIP_Broadcast_Address.s_addr);
-        bip_dest.sin_port = htons(BIP_Port);
-        memset(&(bip_dest.sin_zero), '\0', 8);
-        mtu[1] = BVLC_ORIGINAL_BROADCAST_NPDU;
-    } else
+    } else {
+        /* invalid address */
         return -1;
+    }
 
     mtu_len = 2;
     mtu_len +=
diff --git a/bacnet-stack/ports/linux/arcnet.c b/bacnet-stack/ports/linux/arcnet.c
index efe6410c..ca210394 100644
--- a/bacnet-stack/ports/linux/arcnet.c
+++ b/bacnet-stack/ports/linux/arcnet.c
@@ -350,7 +350,7 @@ void arcnet_get_my_address(BACNET_ADDRESS * my_address)
 
     my_address->mac_len = 1;
     my_address->mac[0] = ARCNET_MAC_Address;
-    my_address->net = 0;        /* local only, no routing */
+    my_address->net = 0;        /* DNET=0 is local only, no routing */
     my_address->len = 0;
     for (i = 0; i < MAX_MAC_LEN; i++) {
         my_address->adr[i] = 0;
@@ -367,7 +367,7 @@ void arcnet_get_broadcast_address(BACNET_ADDRESS * dest)
         dest->mac[0] = ARCNET_BROADCAST;
         dest->mac_len = 1;
         dest->net = BACNET_BROADCAST_NETWORK;
-        dest->len = 0;          /* len=0 denotes broadcast address  */
+        dest->len = 0; /* always zero when DNET is broadcast */
         for (i = 0; i < MAX_MAC_LEN; i++) {
             dest->adr[i] = 0;
         }
diff --git a/bacnet-stack/ports/linux/ethernet.c b/bacnet-stack/ports/linux/ethernet.c
index c9fad44d..d7373d75 100644
--- a/bacnet-stack/ports/linux/ethernet.c
+++ b/bacnet-stack/ports/linux/ethernet.c
@@ -349,7 +349,7 @@ void ethernet_get_my_address(BACNET_ADDRESS * my_address)
         my_address->mac[i] = Ethernet_MAC_Address[i];
         my_address->mac_len++;
     }
-    my_address->net = 0;        /* local only, no routing */
+    my_address->net = 0;        /* DNET=0 is local only, no routing */
     my_address->len = 0;
     for (i = 0; i < MAX_MAC_LEN; i++) {
         my_address->adr[i] = 0;
@@ -368,7 +368,7 @@ void ethernet_get_broadcast_address(BACNET_ADDRESS * dest)
         }
         dest->mac_len = 6;
         dest->net = BACNET_BROADCAST_NETWORK;
-        dest->len = 0;          /* denotes broadcast address  */
+        dest->len = 0; /* always zero when DNET is broadcast */
         for (i = 0; i < MAX_MAC_LEN; i++) {
             dest->adr[i] = 0;
         }
diff --git a/bacnet-stack/ports/pic18f6720/dlmstp.c b/bacnet-stack/ports/pic18f6720/dlmstp.c
index 60c09807..0c045024 100644
--- a/bacnet-stack/ports/pic18f6720/dlmstp.c
+++ b/bacnet-stack/ports/pic18f6720/dlmstp.c
@@ -315,7 +315,7 @@ void dlmstp_get_broadcast_address(BACNET_ADDRESS * dest)
         dest->mac_len = 1;
         dest->mac[0] = MSTP_BROADCAST_ADDRESS;
         dest->net = BACNET_BROADCAST_NETWORK;
-        dest->len = 0;          /* len=0 denotes broadcast address  */
+        dest->len = 0; /* always zero when DNET is broadcast */
         for (i = 0; i < MAX_MAC_LEN; i++) {
             dest->adr[i] = 0;
         }