diff --git a/p2p/simulations/adapters/exec.go b/p2p/simulations/adapters/exec.go
index a566fb27d8..f34ac33043 100644
--- a/p2p/simulations/adapters/exec.go
+++ b/p2p/simulations/adapters/exec.go
@@ -105,9 +105,9 @@ func (e *ExecAdapter) NewNode(config *NodeConfig) (Node, error) {
 	conf.Stack.P2P.NAT = nil
 	conf.Stack.NoUSB = true
 
-	// listen on a random localhost port (we'll get the actual port after
-	// starting the node through the RPC admin.nodeInfo method)
-	conf.Stack.P2P.ListenAddr = "127.0.0.1:0"
+	// listen on a localhost port, which we set when we
+	// initialise NodeConfig (usually a random port)
+	conf.Stack.P2P.ListenAddr = fmt.Sprintf("127.0.0.1:%d", config.Port)
 
 	node := &ExecNode{
 		ID:      config.ID,
diff --git a/p2p/simulations/adapters/types.go b/p2p/simulations/adapters/types.go
index 3f76b19843..2169d68308 100644
--- a/p2p/simulations/adapters/types.go
+++ b/p2p/simulations/adapters/types.go
@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"strconv"
 
 	"github.com/docker/docker/pkg/reexec"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -97,6 +98,8 @@ type NodeConfig struct {
 
 	// function to sanction or prevent suggesting a peer
 	Reachable func(id discover.NodeID) bool
+
+	Port uint16
 }
 
 // nodeConfigJSON is used to encode and decode NodeConfig as JSON by encoding
@@ -106,6 +109,7 @@ type nodeConfigJSON struct {
 	PrivateKey string   `json:"private_key"`
 	Name       string   `json:"name"`
 	Services   []string `json:"services"`
+	Port       uint16   `json:"port"`
 }
 
 // MarshalJSON implements the json.Marshaler interface by encoding the config
@@ -115,6 +119,7 @@ func (n *NodeConfig) MarshalJSON() ([]byte, error) {
 		ID:       n.ID.String(),
 		Name:     n.Name,
 		Services: n.Services,
+		Port:     n.Port,
 	}
 	if n.PrivateKey != nil {
 		confJSON.PrivateKey = hex.EncodeToString(crypto.FromECDSA(n.PrivateKey))
@@ -152,6 +157,7 @@ func (n *NodeConfig) UnmarshalJSON(data []byte) error {
 
 	n.Name = confJSON.Name
 	n.Services = confJSON.Services
+	n.Port = confJSON.Port
 
 	return nil
 }
@@ -165,12 +171,34 @@ func RandomNodeConfig() *NodeConfig {
 	}
 
 	id := discover.PubkeyID(&key.PublicKey)
+	port, err := assignTCPPort()
+	if err != nil {
+		panic("unable to assign tcp port")
+	}
 	return &NodeConfig{
 		ID:         id,
 		PrivateKey: key,
+		Port:       port,
 	}
 }
 
+func assignTCPPort() (uint16, error) {
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		return 0, err
+	}
+	l.Close()
+	_, port, err := net.SplitHostPort(l.Addr().String())
+	if err != nil {
+		return 0, err
+	}
+	p, err := strconv.ParseInt(port, 10, 32)
+	if err != nil {
+		return 0, err
+	}
+	return uint16(p), nil
+}
+
 // ServiceContext is a collection of options and methods which can be utilised
 // when starting services
 type ServiceContext struct {
diff --git a/swarm/network/protocol.go b/swarm/network/protocol.go
index 9afa69c3a9..448e722269 100644
--- a/swarm/network/protocol.go
+++ b/swarm/network/protocol.go
@@ -402,6 +402,15 @@ func NewAddrFromNodeID(id discover.NodeID) *BzzAddr {
 	}
 }
 
+// NewAddrFromNodeIDAndPort constucts a BzzAddr from a discover.NodeID and port uint16
+// the overlay address is derived as the hash of the nodeID
+func NewAddrFromNodeIDAndPort(id discover.NodeID, port uint16) *BzzAddr {
+	return &BzzAddr{
+		OAddr: ToOverlayAddr(id.Bytes()),
+		UAddr: []byte(discover.NewNode(id, net.IP{127, 0, 0, 1}, port, port).String()),
+	}
+}
+
 // ToOverlayAddr creates an overlayaddress from a byte slice
 func ToOverlayAddr(id []byte) []byte {
 	return crypto.Keccak256(id)
diff --git a/swarm/network/simulations/discovery/discovery_test.go b/swarm/network/simulations/discovery/discovery_test.go
index 63674c3c02..cc4373483b 100644
--- a/swarm/network/simulations/discovery/discovery_test.go
+++ b/swarm/network/simulations/discovery/discovery_test.go
@@ -139,7 +139,7 @@ func benchmarkDiscovery(b *testing.B, nodes, conns int) {
 	for i := 0; i < b.N; i++ {
 		result, err := discoverySimulation(nodes, conns, adapters.NewSimAdapter(services))
 		if err != nil {
-			b.Fatalf("setting up simulation failed", result)
+			b.Fatalf("setting up simulation failed: %s", err)
 		}
 		if result.Error != nil {
 			b.Logf("simulation failed: %s", result.Error)
@@ -297,7 +297,7 @@ func triggerChecks(trigger chan discover.NodeID, net *simulations.Network, id di
 }
 
 func newService(ctx *adapters.ServiceContext) (node.Service, error) {
-	addr := network.NewAddrFromNodeID(ctx.Config.ID)
+	addr := network.NewAddrFromNodeIDAndPort(ctx.Config.ID, ctx.Config.Port)
 
 	kp := network.NewKadParams()
 	kp.MinProxBinSize = testMinProxBinSize