diff --git a/report/id_list.go b/report/id_list.go
index 1c05b582a..9d89d7d08 100644
--- a/report/id_list.go
+++ b/report/id_list.go
@@ -24,3 +24,9 @@ func (a IDList) Add(ids ...string) IDList {
 	}
 	return a
 }
+
+// Contains returns true if id is in the list.
+func (a IDList) Contains(id string) bool {
+	i := sort.Search(len(a), func(i int) bool { return a[i] >= id })
+	return i < len(a) && a[i] == id
+}
diff --git a/report/report.go b/report/report.go
index 460e19f4d..5cc5ebae5 100644
--- a/report/report.go
+++ b/report/report.go
@@ -122,3 +122,18 @@ func (r Report) LocalNetworks() []*net.IPNet {
 	}
 	return ipNets
 }
+
+// Topologies returns a slice of Topologies in this report
+func (r Report) Topologies() []Topology {
+	return []Topology{r.Endpoint, r.Address, r.Process, r.Container, r.Host}
+}
+
+// Validate checks the report for various inconsistencies.
+func (r Report) Validate() error {
+	for _, topology := range r.Topologies() {
+		if err := topology.Validate(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/report/topology.go b/report/topology.go
index f9abed7c6..ed8a68ed8 100644
--- a/report/topology.go
+++ b/report/topology.go
@@ -1,6 +1,7 @@
 package report
 
 import (
+	"fmt"
 	"log"
 	"net"
 	"reflect"
@@ -266,3 +267,46 @@ type ByID []RenderableNode
 func (r ByID) Len() int           { return len(r) }
 func (r ByID) Swap(i, j int)      { r[i], r[j] = r[j], r[i] }
 func (r ByID) Less(i, j int) bool { return r[i].ID < r[j].ID }
+
+// Validate checks the topology for various inconsistencies.
+func (t Topology) Validate() error {
+	// Check all edge metadata keys must have the appropriate entries in adjacencies & node metadata
+	for edgeID := range t.EdgeMetadatas {
+		srcNodeID, dstNodeID, ok := ParseEdgeID(edgeID)
+		if !ok {
+			return fmt.Errorf("Invalid edge id: %s", edgeID)
+		}
+		if _, ok := t.NodeMetadatas[srcNodeID]; !ok {
+			return fmt.Errorf("Source node missing for edge id: %s", edgeID)
+		}
+
+		adjs, ok := t.Adjacency[MakeAdjacencyID(srcNodeID)]
+		if !ok {
+			return fmt.Errorf("Adjancey entries for missing for node id: %s (from edge %s)", srcNodeID, edgeID)
+		}
+		if !adjs.Contains(dstNodeID) {
+			return fmt.Errorf("Adjancey entry missing for edge id: %s", edgeID)
+		}
+	}
+
+	// Check all adjancency keys has entries in NodeMetadata
+	for adjID := range t.Adjacency {
+		nodeID, ok := ParseAdjacencyID(adjID)
+		if !ok {
+			return fmt.Errorf("Invalid adjacency id: %s", adjID)
+		}
+
+		if _, ok := t.NodeMetadatas[nodeID]; !ok {
+			return fmt.Errorf("Source node missing for adjancency id: %s", adjID)
+		}
+	}
+
+	// Check all node metadata keys are parse-able (ie, contain a scope)
+	for nodeID := range t.NodeMetadatas {
+		if _, _, ok := ParseNodeID(nodeID); !ok {
+			return fmt.Errorf("Invalid node id: %s", nodeID)
+		}
+	}
+
+	return nil
+}
diff --git a/xfer/collector.go b/xfer/collector.go
index a7e49d879..464d8e8fe 100644
--- a/xfer/collector.go
+++ b/xfer/collector.go
@@ -102,6 +102,10 @@ func (c *realCollector) loop(batchTime time.Duration) {
 			pc <- copy
 
 		case r := <-c.in:
+			if err := r.Validate(); err != nil {
+				log.Printf("Received invalid report from: %v", err)
+				continue
+			}
 			current.Merge(r)
 
 		case ip := <-c.add:
diff --git a/xfer/collector_test.go b/xfer/collector_test.go
index 97f67f651..5d0d4889c 100644
--- a/xfer/collector_test.go
+++ b/xfer/collector_test.go
@@ -42,7 +42,7 @@ func TestCollector(t *testing.T) {
 	runtime.Gosched()   // make sure it connects
 
 	// Push a report through everything
-	reports <- report.Report{Address: report.Topology{NodeMetadatas: report.NodeMetadatas{"a": report.NodeMetadata{}}}}
+	reports <- report.Report{Address: report.Topology{NodeMetadatas: report.NodeMetadatas{report.MakeAddressNodeID("a", "b"): report.NodeMetadata{}}}}
 	poll(t, 10*time.Millisecond, func() bool { return len(concreteCollector.peek().Address.NodeMetadatas) == 1 }, "missed the report")
 	go func() { publish <- time.Now() }()
 	if want, have := 1, len((<-collector.Reports()).Address.NodeMetadatas); want != have {
diff --git a/xfer/merge_test.go b/xfer/merge_test.go
index 2bfe4e603..53ca89ec7 100644
--- a/xfer/merge_test.go
+++ b/xfer/merge_test.go
@@ -37,14 +37,16 @@ func TestMerge(t *testing.T) {
 	defer c.Stop()
 	time.Sleep(batchTime / 10) // connect
 
+	k1, k2 := report.MakeHostNodeID("p1"), report.MakeHostNodeID("p2")
+
 	{
 		r := report.MakeReport()
-		r.Host.NodeMetadatas["p1"] = report.NodeMetadata{"host_name": "test1"}
+		r.Host.NodeMetadatas[k1] = report.NodeMetadata{"host_name": "test1"}
 		p1.Publish(r)
 	}
 	{
 		r := report.MakeReport()
-		r.Host.NodeMetadatas["p2"] = report.NodeMetadata{"host_name": "test2"}
+		r.Host.NodeMetadatas[k2] = report.NodeMetadata{"host_name": "test2"}
 		p2.Publish(r)
 	}
 
@@ -52,10 +54,10 @@ func TestMerge(t *testing.T) {
 	go func() {
 		defer close(success)
 		for r := range c.Reports() {
-			if r.Host.NodeMetadatas["p1"]["host_name"] != "test1" {
+			if r.Host.NodeMetadatas[k1]["host_name"] != "test1" {
 				continue
 			}
-			if r.Host.NodeMetadatas["p2"]["host_name"] != "test2" {
+			if r.Host.NodeMetadatas[k2]["host_name"] != "test2" {
 				continue
 			}
 			return