diff --git a/nat/nat.go b/nat/nat.go
index 76beb2b..9fe97f6 100644
--- a/nat/nat.go
+++ b/nat/nat.go
@@ -1,3 +1,6 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
 package nat
 
 import (
@@ -10,14 +13,14 @@ import (
 )
 
 const (
-	mapTimeout       = 30 * time.Minute
+	mapTimeout       = 30 * time.Second
 	mapUpdateTimeout = mapTimeout / 2
 	maxRetries       = 20
 )
 
 type NATRouter interface {
 	MapPort(protocol string, intPort, extPort uint16, desc string, duration time.Duration) error
-	UnmapPort(protocol string, extPort uint16) error
+	UnmapPort(protocol string, intPort, extPort uint16) error
 	ExternalIP() (net.IP, error)
 	GetPortMappingEntry(extPort uint16, protocol string) (
 		InternalIP string,
@@ -28,10 +31,12 @@ type NATRouter interface {
 }
 
 func GetNATRouter() NATRouter {
-	//TODO add PMP support
 	if r := getUPnPRouter(); r != nil {
 		return r
 	}
+	if r := getPMPRouter(); r != nil {
+		return r
+	}
 
 	return NewNoRouter()
 }
@@ -95,11 +100,9 @@ func (dev *Mapper) keepPortMapping(mappedPort chan<- uint16, protocol string,
 				updateTimer.Stop()
 
 				dev.log.Info("Unmap protocol %s external port %d", protocol, port)
-				if port > 0 {
-					dev.errLock.Lock()
-					dev.errs.Add(dev.r.UnmapPort(protocol, port))
-					dev.errLock.Unlock()
-				}
+				dev.errLock.Lock()
+				dev.errs.Add(dev.r.UnmapPort(protocol, intPort, port))
+				dev.errLock.Unlock()
 
 				dev.wg.Done()
 			}(port)
@@ -120,7 +123,6 @@ func (dev *Mapper) keepPortMapping(mappedPort chan<- uint16, protocol string,
 					return
 				}
 			}
-			break
 		}
 	}
 
diff --git a/nat/no_router.go b/nat/no_router.go
index 07ac025..7a15601 100644
--- a/nat/no_router.go
+++ b/nat/no_router.go
@@ -1,3 +1,6 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
 package nat
 
 import (
@@ -12,14 +15,14 @@ type noRouter struct {
 	ip net.IP
 }
 
-func (noRouter) MapPort(protocol string, intport, extport uint16, desc string, duration time.Duration) error {
-	if intport != extport {
-		return fmt.Errorf("cannot map port %d to %d", intport, extport)
+func (noRouter) MapPort(_ string, intPort, extPort uint16, _ string, _ time.Duration) error {
+	if intPort != extPort {
+		return fmt.Errorf("cannot map port %d to %d", intPort, extPort)
 	}
 	return nil
 }
 
-func (noRouter) UnmapPort(protocol string, extport uint16) error {
+func (noRouter) UnmapPort(string, uint16, uint16) error {
 	return nil
 }
 
diff --git a/nat/pmp.go b/nat/pmp.go
new file mode 100644
index 0000000..7c5a800
--- /dev/null
+++ b/nat/pmp.go
@@ -0,0 +1,78 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package nat
+
+import (
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/jackpal/gateway"
+	"github.com/jackpal/go-nat-pmp"
+)
+
+var (
+	pmpClientTimeout = 500 * time.Millisecond
+)
+
+// natPMPClient adapts the NAT-PMP protocol implementation so it conforms to
+// the common interface.
+type pmpRouter struct {
+	client *natpmp.Client
+}
+
+func (pmp *pmpRouter) MapPort(
+	networkProtocol string,
+	newInternalPort uint16,
+	newExternalPort uint16,
+	mappingName string,
+	mappingDuration time.Duration) error {
+	protocol := string(networkProtocol)
+	internalPort := int(newInternalPort)
+	externalPort := int(newExternalPort)
+	// go-nat-pmp uses seconds to denote their lifetime
+	lifetime := int(mappingDuration / time.Second)
+
+	_, err := pmp.client.AddPortMapping(protocol, internalPort, externalPort, lifetime)
+	return err
+}
+
+func (pmp *pmpRouter) UnmapPort(
+	networkProtocol string,
+	internalPort uint16,
+	_ uint16) error {
+	protocol := string(networkProtocol)
+	internalPortInt := int(internalPort)
+
+	_, err := pmp.client.AddPortMapping(protocol, internalPortInt, 0, 0)
+	return err
+}
+
+func (pmp *pmpRouter) ExternalIP() (net.IP, error) {
+	response, err := pmp.client.GetExternalAddress()
+	if err != nil {
+		return nil, err
+	}
+	return response.ExternalIPAddress[:], nil
+}
+
+// go-nat-pmp does not support port mapping entry query
+func (pmp *pmpRouter) GetPortMappingEntry(externalPort uint16, protocol string) (
+	string, uint16, string, error) {
+	return "", 0, "", fmt.Errorf("port mapping entry not found")
+}
+
+func getPMPRouter() *pmpRouter {
+	gatewayIP, err := gateway.DiscoverGateway()
+	if err != nil {
+		return nil
+	}
+
+	pmp := &pmpRouter{natpmp.NewClientWithTimeout(gatewayIP, pmpClientTimeout)}
+	if _, err := pmp.ExternalIP(); err != nil {
+		return nil
+	}
+
+	return pmp
+}
diff --git a/nat/upnp.go b/nat/upnp.go
index 863544e..3191bc8 100644
--- a/nat/upnp.go
+++ b/nat/upnp.go
@@ -1,3 +1,6 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
 package nat
 
 import (
@@ -119,7 +122,7 @@ func (r *upnpRouter) MapPort(protocol string, intPort, extPort uint16,
 		ip.String(), true, desc, lifetime)
 }
 
-func (r *upnpRouter) UnmapPort(protocol string, extPort uint16) error {
+func (r *upnpRouter) UnmapPort(protocol string, _, extPort uint16) error {
 	return r.client.DeletePortMapping("", extPort, protocol)
 }