diff --git a/ctdb/server/ipalloc.c b/ctdb/server/ipalloc.c
index e18c8994b87..bacbdb32aee 100644
--- a/ctdb/server/ipalloc.c
+++ b/ctdb/server/ipalloc.c
@@ -67,7 +67,7 @@ static void *add_ip_callback(void *parm, void *data)
 	if (prev_ip == NULL) {
 		return parm;
 	}
-	if (this_ip->pnn == -1) {
+	if (this_ip->pnn == CTDB_UNKNOWN_PNN) {
 		this_ip->pnn = prev_ip->pnn;
 	}
 
@@ -125,7 +125,7 @@ create_merged_ip_list(struct ipalloc_state *ipalloc_state)
 			if (public_ips->ip[j].pnn == i) {
 				tmp_ip->pnn = public_ips->ip[j].pnn;
 			} else {
-				tmp_ip->pnn = -1;
+				tmp_ip->pnn = CTDB_UNKNOWN_PNN;
 			}
 			tmp_ip->addr = public_ips->ip[j].addr;
 			tmp_ip->next = NULL;
@@ -272,7 +272,7 @@ struct public_ip_list *ipalloc(struct ipalloc_state *ipalloc_state)
 	}
 
 	/* at this point ->pnn is the node which will own each IP
-	   or -1 if there is no node that can cover this ip
+	   or CTDB_UNKNOWN_PNN if there is no node that can cover this ip
 	*/
 
 	return (ret ? ipalloc_state->all_ips : NULL);
diff --git a/ctdb/server/ipalloc_common.c b/ctdb/server/ipalloc_common.c
index a0152e3285d..53d96d11e47 100644
--- a/ctdb/server/ipalloc_common.c
+++ b/ctdb/server/ipalloc_common.c
@@ -87,7 +87,7 @@ int find_takeover_node(struct ipalloc_state *ipalloc_state,
 	unsigned int i, numnodes;
 
 	numnodes = ipalloc_state->num;
-	pnn    = -1;
+	pnn = CTDB_UNKNOWN_PNN;
 	for (i=0; i<numnodes; i++) {
 		/* verify that this node can serve this ip */
 		if (!can_node_takeover_ip(ipalloc_state, i, ip)) {
@@ -97,7 +97,7 @@ int find_takeover_node(struct ipalloc_state *ipalloc_state,
 
 		num = node_ip_coverage(i, ipalloc_state->all_ips);
 		/* was this the first node we checked ? */
-		if (pnn == -1) {
+		if (pnn == CTDB_UNKNOWN_PNN) {
 			pnn = i;
 			min  = num;
 		} else {
@@ -107,7 +107,7 @@ int find_takeover_node(struct ipalloc_state *ipalloc_state,
 			}
 		}
 	}
-	if (pnn == -1) {
+	if (pnn == CTDB_UNKNOWN_PNN) {
 		DEBUG(DEBUG_WARNING,(__location__ " Could not find node to take over public address '%s'\n",
 				     ctdb_sock_addr_to_string(ipalloc_state,
 							      &ip->addr,
@@ -157,7 +157,7 @@ void basic_allocate_unassigned(struct ipalloc_state *ipalloc_state)
 	   each unassigned ip.
 	*/
 	for (t = ipalloc_state->all_ips; t != NULL; t = t->next) {
-		if (t->pnn == -1) {
+		if (t->pnn == CTDB_UNKNOWN_PNN) {
 			if (find_takeover_node(ipalloc_state, t)) {
 				DEBUG(DEBUG_WARNING,
 				      ("Failed to find node to cover ip %s\n",
@@ -174,10 +174,10 @@ void unassign_unsuitable_ips(struct ipalloc_state *ipalloc_state)
 	struct public_ip_list *t;
 
 	/* verify that the assigned nodes can serve that public ip
-	   and set it to -1 if not
+	   and set it to CTDB_UNKNOWN_PNN if not
 	*/
 	for (t = ipalloc_state->all_ips; t != NULL; t = t->next) {
-		if (t->pnn == -1) {
+		if (t->pnn == CTDB_UNKNOWN_PNN) {
 			continue;
 		}
 		if (!can_node_host_ip(ipalloc_state, t->pnn, t) != 0) {
@@ -187,7 +187,7 @@ void unassign_unsuitable_ips(struct ipalloc_state *ipalloc_state)
 						   ipalloc_state,
 						   &t->addr, false),
 					   t->pnn));
-			t->pnn = -1;
+			t->pnn = CTDB_UNKNOWN_PNN;
 		}
 	}
 }
diff --git a/ctdb/server/ipalloc_lcp2.c b/ctdb/server/ipalloc_lcp2.c
index dc42a852edb..6993e7a7014 100644
--- a/ctdb/server/ipalloc_lcp2.c
+++ b/ctdb/server/ipalloc_lcp2.c
@@ -164,7 +164,7 @@ static bool lcp2_init(struct ipalloc_state *ipalloc_state,
 	 * changes.
 	 */
 	for (t = ipalloc_state->all_ips; t != NULL; t = t->next) {
-		if (t->pnn != -1) {
+		if (t->pnn != CTDB_UNKNOWN_PNN) {
 			(*rebalance_candidates)[t->pnn] = false;
 		}
 	}
@@ -217,13 +217,13 @@ static void lcp2_allocate_unassigned(struct ipalloc_state *ipalloc_state,
 		DEBUG(DEBUG_DEBUG,(" ----------------------------------------\n"));
 		DEBUG(DEBUG_DEBUG,(" CONSIDERING MOVES (UNASSIGNED)\n"));
 
-		minnode = -1;
+		minnode = CTDB_UNKNOWN_PNN;
 		mindsum = 0;
 		minip = NULL;
 
 		/* loop over each unassigned ip. */
 		for (t = ipalloc_state->all_ips; t != NULL ; t = t->next) {
-			if (t->pnn != -1) {
+			if (t->pnn != CTDB_UNKNOWN_PNN) {
 				continue;
 			}
 
@@ -249,7 +249,8 @@ static void lcp2_allocate_unassigned(struct ipalloc_state *ipalloc_state,
 				       dstimbl - lcp2_imbalances[dstnode]));
 
 
-				if ((minnode == -1) || (dstdsum < mindsum)) {
+				if (minnode == CTDB_UNKNOWN_PNN ||
+				    dstdsum < mindsum) {
 					minnode = dstnode;
 					minimbl = dstimbl;
 					mindsum = dstdsum;
@@ -262,7 +263,7 @@ static void lcp2_allocate_unassigned(struct ipalloc_state *ipalloc_state,
 		DEBUG(DEBUG_DEBUG,(" ----------------------------------------\n"));
 
 		/* If we found one then assign it to the given node. */
-		if (minnode != -1) {
+		if (minnode != CTDB_UNKNOWN_PNN) {
 			minip->pnn = minnode;
 			lcp2_imbalances[minnode] = minimbl;
 			DEBUG(DEBUG_INFO,(" %s -> %d [+%d]\n",
@@ -276,7 +277,7 @@ static void lcp2_allocate_unassigned(struct ipalloc_state *ipalloc_state,
 		/* There might be a better way but at least this is clear. */
 		have_unassigned = false;
 		for (t = ipalloc_state->all_ips; t != NULL; t = t->next) {
-			if (t->pnn == -1) {
+			if (t->pnn == CTDB_UNKNOWN_PNN) {
 				have_unassigned = true;
 			}
 		}
@@ -287,7 +288,7 @@ static void lcp2_allocate_unassigned(struct ipalloc_state *ipalloc_state,
 	 */
 	if (have_unassigned) {
 		for (t = ipalloc_state->all_ips; t != NULL; t = t->next) {
-			if (t->pnn == -1) {
+			if (t->pnn == CTDB_UNKNOWN_PNN) {
 				DEBUG(DEBUG_WARNING,
 				      ("Failed to find node to cover ip %s\n",
 				       ctdb_sock_addr_to_string(ipalloc_state,
@@ -317,7 +318,7 @@ static bool lcp2_failback_candidate(struct ipalloc_state *ipalloc_state,
 	srcimbl = 0;
 	minip = NULL;
 	minsrcimbl = 0;
-	mindstnode = -1;
+	mindstnode = CTDB_UNKNOWN_PNN;
 	mindstimbl = 0;
 
 	numnodes = ipalloc_state->num;
@@ -369,7 +370,7 @@ static bool lcp2_failback_candidate(struct ipalloc_state *ipalloc_state,
 
 			if ((dstimbl < lcp2_imbalances[srcnode]) &&
 			    (dstdsum < srcdsum) &&			\
-			    ((mindstnode == -1) ||				\
+			    ((mindstnode == CTDB_UNKNOWN_PNN) ||				\
 			     ((srcimbl + dstimbl) < (minsrcimbl + mindstimbl)))) {
 
 				minip = t;
@@ -381,7 +382,7 @@ static bool lcp2_failback_candidate(struct ipalloc_state *ipalloc_state,
 	}
 	DEBUG(DEBUG_DEBUG,(" ----------------------------------------\n"));
 
-        if (mindstnode != -1) {
+        if (mindstnode != CTDB_UNKNOWN_PNN) {
 		/* We found a move that makes things better... */
 		DEBUG(DEBUG_INFO,
 		      ("%d [%d] -> %s -> %d [+%d]\n",
diff --git a/ctdb/server/ipalloc_nondeterministic.c b/ctdb/server/ipalloc_nondeterministic.c
index 3c2bdea06cb..1e70c8b78a2 100644
--- a/ctdb/server/ipalloc_nondeterministic.c
+++ b/ctdb/server/ipalloc_nondeterministic.c
@@ -54,15 +54,15 @@ try_again:
 	   not greater than 1.
 	*/
 	for (t = ipalloc_state->all_ips; t != NULL; t = t->next) {
-		if (t->pnn == -1) {
+		if (t->pnn == CTDB_UNKNOWN_PNN) {
 			continue;
 		}
 
 		/* Get the highest and lowest number of ips's served by any 
 		   valid node which can serve this ip.
 		*/
-		maxnode = -1;
-		minnode = -1;
+		maxnode = CTDB_UNKNOWN_PNN;
+		minnode = CTDB_UNKNOWN_PNN;
 		for (i=0; i<numnodes; i++) {
 			/* only check nodes that can actually serve this ip */
 			if (!can_node_takeover_ip(ipalloc_state, i,
@@ -72,7 +72,7 @@ try_again:
 			}
 
 			num = node_ip_coverage(i, ipalloc_state->all_ips);
-			if (maxnode == -1) {
+			if (maxnode == CTDB_UNKNOWN_PNN) {
 				maxnode = i;
 				maxnum  = num;
 			} else {
@@ -81,7 +81,7 @@ try_again:
 					maxnum  = num;
 				}
 			}
-			if (minnode == -1) {
+			if (minnode == CTDB_UNKNOWN_PNN) {
 				minnode = i;
 				minnum  = num;
 			} else {
@@ -91,7 +91,7 @@ try_again:
 				}
 			}
 		}
-		if (maxnode == -1) {
+		if (maxnode == CTDB_UNKNOWN_PNN) {
 			DEBUG(DEBUG_WARNING,
 			      (__location__ " Could not find maxnode. May not be able to serve ip '%s'\n",
 			       ctdb_sock_addr_to_string(ipalloc_state,