diff --git a/beacon_chain/conf.nim b/beacon_chain/conf.nim
index 2306dfd72..cb63536b3 100644
--- a/beacon_chain/conf.nim
+++ b/beacon_chain/conf.nim
@@ -5,7 +5,7 @@ import
   chronicles, chronicles/options as chroniclesOptions,
   confutils, confutils/defs, confutils/std/net, stew/shims/net as stewNet,
   stew/io2, unicodedb/properties, normalize,
-  eth/common/eth_types as commonEthTypes,
+  eth/common/eth_types as commonEthTypes, eth/net/nat,
   eth/p2p/discoveryv5/enr,
   json_serialization, web3/[ethtypes, confutils_defs],
   spec/[crypto, keystore, digest, datatypes, network],
@@ -170,7 +170,8 @@ type
       nat* {.
         desc: "Specify method to use for determining public address. " &
               "Must be one of: any, none, upnp, pmp, extip:<IP>"
-        defaultValue: "any" }: string
+        defaultValue: NatConfig(hasExtIp: false, nat: NatAny)
+        name: "nat" .}: NatConfig
 
       enrAutoUpdate* {.
         defaultValue: false
diff --git a/beacon_chain/networking/eth2_discovery.nim b/beacon_chain/networking/eth2_discovery.nim
index 06b27870e..3269c0ae1 100644
--- a/beacon_chain/networking/eth2_discovery.nim
+++ b/beacon_chain/networking/eth2_discovery.nim
@@ -75,7 +75,7 @@ proc loadBootstrapFile*(bootstrapFile: string,
 
 proc new*(T: type Eth2DiscoveryProtocol,
           config: BeaconNodeConf,
-          ip: Option[ValidIpAddress], tcpPort, udpPort: Port,
+          enrIp: Option[ValidIpAddress], enrTcpPort, enrUdpPort: Option[Port],
           pk: PrivateKey,
           enrFields: openArray[(string, seq[byte])], rng: ref BrHmacDrbgContext):
           T {.raises: [Exception, Defect].} =
@@ -92,6 +92,6 @@ proc new*(T: type Eth2DiscoveryProtocol,
   if fileExists(persistentBootstrapFile):
     loadBootstrapFile(persistentBootstrapFile, bootstrapEnrs)
 
-  newProtocol(pk, ip, tcpPort, udpPort, enrFields, bootstrapEnrs,
-    bindIp = config.listenAddress, enrAutoUpdate = config.enrAutoUpdate,
-    rng = rng)
+  newProtocol(pk, enrIp, enrTcpPort, enrUdpPort, enrFields, bootstrapEnrs,
+    bindPort = config.udpPort, bindIp = config.listenAddress,
+    enrAutoUpdate = config.enrAutoUpdate, rng = rng)
diff --git a/beacon_chain/networking/eth2_network.nim b/beacon_chain/networking/eth2_network.nim
index 0a59c0058..d505cfd06 100644
--- a/beacon_chain/networking/eth2_network.nim
+++ b/beacon_chain/networking/eth2_network.nim
@@ -1062,7 +1062,7 @@ proc onConnEvent(node: Eth2Node, peerId: PeerID, event: ConnEvent) {.async.} =
 
 proc new*(T: type Eth2Node, config: BeaconNodeConf, enrForkId: ENRForkID,
           switch: Switch, pubsub: GossipSub, ip: Option[ValidIpAddress],
-          tcpPort, udpPort: Port, privKey: keys.PrivateKey, discovery: bool,
+          tcpPort, udpPort: Option[Port], privKey: keys.PrivateKey, discovery: bool,
           rng: ref BrHmacDrbgContext): T =
   let
     metadata = getPersistentNetMetadata(config)
@@ -1315,49 +1315,6 @@ proc p2pProtocolBackendImpl*(p: P2PProtocol): Backend =
   result.implementProtocolInit = proc (p: P2PProtocol): NimNode =
     return newCall(initProtocol, newLit(p.name), p.peerInit, p.netInit)
 
-proc setupNat(config: BeaconNodeConf): tuple[ip: Option[ValidIpAddress],
-                                           tcpPort: Port,
-                                           udpPort: Port] =
-  # defaults
-  result.tcpPort = config.tcpPort
-  result.udpPort = config.udpPort
-
-  var nat: NatStrategy
-  case config.nat.toLowerAscii:
-    of "any":
-      nat = NatAny
-    of "none":
-      nat = NatNone
-    of "upnp":
-      nat = NatUpnp
-    of "pmp":
-      nat = NatPmp
-    else:
-      if config.nat.startsWith("extip:"):
-        try:
-          # any required port redirection is assumed to be done by hand
-          result.ip = some(ValidIpAddress.init(config.nat[6..^1]))
-          nat = NatNone
-        except ValueError:
-          error "nor a valid IP address", address = config.nat[6..^1]
-          quit QuitFailure
-      else:
-        error "not a valid NAT mechanism", value = config.nat
-        quit QuitFailure
-
-  if nat != NatNone:
-    let extIp = getExternalIP(nat)
-    if extIP.isSome:
-      result.ip = some(ValidIpAddress.init extIp.get)
-      # TODO redirectPorts in considered a gcsafety violation
-      # because it obtains the address of a non-gcsafe proc?
-      let extPorts = ({.gcsafe.}:
-        redirectPorts(tcpPort = result.tcpPort,
-                      udpPort = result.udpPort,
-                      description = clientId))
-      if extPorts.isSome:
-        (result.tcpPort, result.udpPort) = extPorts.get()
-
 func asLibp2pKey*(key: keys.PublicKey): PublicKey =
   PublicKey(scheme: Secp256k1, skkey: secp.SkPublicKey(key))
 
@@ -1540,10 +1497,11 @@ proc createEth2Node*(rng: ref BrHmacDrbgContext,
                      netKeys: KeyPair,
                      enrForkId: ENRForkID): Eth2Node =
   var
-    (extIp, extTcpPort, extUdpPort) = setupNat(config)
+    (extIp, extTcpPort, extUdpPort) = setupAddress(config.nat,
+      config.listenAddress, config.tcpPort, config.udpPort, clientId)
     hostAddress = tcpEndPoint(config.listenAddress, config.tcpPort)
-    announcedAddresses = if extIp.isNone(): @[]
-                         else: @[tcpEndPoint(extIp.get(), extTcpPort)]
+    announcedAddresses = if extIp.isNone() or extTcpPort.isNone(): @[]
+                         else: @[tcpEndPoint(extIp.get(), extTcpPort.get())]
 
   debug "Initializing networking", hostAddress,
                                    network_public_key = netKeys.pubkey,
diff --git a/beacon_chain/nimbus_beacon_node.nim b/beacon_chain/nimbus_beacon_node.nim
index 3266192cf..dda6385f4 100644
--- a/beacon_chain/nimbus_beacon_node.nim
+++ b/beacon_chain/nimbus_beacon_node.nim
@@ -17,7 +17,7 @@ import
   chronicles, bearssl, blscurve,
   json_serialization/std/[options, sets, net], serialization/errors,
 
-  eth/[keys, async_utils],
+  eth/[keys, async_utils], eth/net/nat,
   eth/db/[kvstore, kvstore_sqlite3],
   eth/p2p/enode, eth/p2p/discoveryv5/[protocol, enr, random2],
 
diff --git a/ncli/inspector.nim b/ncli/inspector.nim
index bc1dd82e9..9b6686858 100644
--- a/ncli/inspector.nim
+++ b/ncli/inspector.nim
@@ -412,9 +412,11 @@ proc bootstrapDiscovery(conf: InspectorConf,
   if enrFields.isSome():
     let fields = enrFields.get()
     let pairs = {"eth2": fields.eth2, "attnets": fields.attnets}
-    result = newProtocol(pk, host, tcpPort, udpPort, pairs, bootnodes)
+    result = newProtocol(pk, host, some(tcpPort), some(udpPort), pairs,
+      bootnodes, bindPort = udpPort)
   else:
-    result = newProtocol(pk, host, tcpPort, udpPort, [], bootnodes)
+    result = newProtocol(pk, host, some(tcpPort), some(udpPort), [],
+      bootnodes, bindPort = udpPort)
   result.open()
   result.start()
 
diff --git a/vendor/nim-chronos b/vendor/nim-chronos
index 25688cd0a..03707426e 160000
--- a/vendor/nim-chronos
+++ b/vendor/nim-chronos
@@ -1 +1 @@
-Subproject commit 25688cd0aa51f5e28c1e55dca1b3a9a73cb3dafa
+Subproject commit 03707426e43d03cccc1de2e7284de168b79f7bf6
diff --git a/vendor/nim-eth b/vendor/nim-eth
index e8c9691b3..be5e088b2 160000
--- a/vendor/nim-eth
+++ b/vendor/nim-eth
@@ -1 +1 @@
-Subproject commit e8c9691b35f4875d9a97193cb965fbf1a956dd7e
+Subproject commit be5e088b21e06a85cac4826454412db8459ed4f1