diff --git a/libp2p/Host.cpp b/libp2p/Host.cpp
index 392d02dc4..5f756f2a5 100644
--- a/libp2p/Host.cpp
+++ b/libp2p/Host.cpp
@@ -401,7 +401,7 @@ void Host::connect(NodeId const& _node, std::string const& _addr, unsigned short
 	
 	assert(_node);
 
-	auto n = m_nodes[_node];
+	auto n = (*m_nodeTable)[_node];
 	
 	// TODO: refactor into async_resolve
 	m_ioService.post([=]()
@@ -619,14 +619,8 @@ void Host::run(boost::system::error_code const&)
 		if (auto pp = p.second.lock())
 			pp->serviceNodesRequest();
 	
-	if (chrono::steady_clock::now() - m_lastPing > chrono::seconds(30))	// ping every 30s.
-	{
-		for (auto p: m_peers)
-			if (auto pp = p.second.lock())
-				if (chrono::steady_clock::now() - pp->m_lastReceived > chrono::seconds(60))
-					pp->disconnect(PingTimeout);
-		pingAll();
-	}
+	if (chrono::steady_clock::now() - m_lastPing >= chrono::seconds(30))	// ping every 30s.
+		keepAlivePeers();
 	
 	auto runcb = [this](boost::system::error_code const& error) -> void { run(error); };
 	m_timer->expires_from_now(boost::posix_time::milliseconds(c_timerInterval));
@@ -680,12 +674,18 @@ void Host::doWork()
 		m_ioService.run();
 }
 
-void Host::pingAll()
+void Host::keepAlivePeers()
 {
 	RecursiveGuard l(x_peers);
-	for (auto& i: m_peers)
-		if (auto j = i.second.lock())
-			j->ping();
+	for (auto p: m_peers)
+		if (auto pp = p.second.lock())
+		{
+			if (chrono::steady_clock::now() - pp->m_lastReceived >= chrono::seconds(60))
+				pp->disconnect(PingTimeout);
+			else
+				pp->ping();
+		}
+
 	m_lastPing = chrono::steady_clock::now();
 }
 
diff --git a/libp2p/Host.h b/libp2p/Host.h
index edfa79df3..5892b5b0d 100644
--- a/libp2p/Host.h
+++ b/libp2p/Host.h
@@ -165,8 +165,8 @@ public:
 	/// Get number of peers connected; equivalent to, but faster than, peers().size().
 	size_t peerCount() const { RecursiveGuard l(x_peers); return m_peers.size(); }
 
-	/// Ping the peers, to update the latency information.
-	void pingAll();
+	/// Ping the peers to update the latency information and disconnect peers which have timed out.
+	void keepAlivePeers();
 
 	/// Get the port we're listening on currently.
 	unsigned short listenPort() const { return m_tcpPublic.port(); }
diff --git a/libp2p/NodeTable.cpp b/libp2p/NodeTable.cpp
index 53acc9dbe..1b74abbda 100644
--- a/libp2p/NodeTable.cpp
+++ b/libp2p/NodeTable.cpp
@@ -77,10 +77,11 @@ list<NodeEntry> NodeTable::state() const
 	return move(ret);
 }
 
-NodeEntry NodeTable::operator[](NodeId _id)
+Node NodeTable::operator[](NodeId _id)
 {
 	Guard l(x_nodes);
-	return *m_nodes[_id];
+	auto n = m_nodes[_id];
+	return !!n ? *n : Node();
 }
 
 void NodeTable::requestNeighbours(NodeEntry const& _node, NodeId _target) const
diff --git a/libp2p/NodeTable.h b/libp2p/NodeTable.h
index 89bd68be1..79ce6a9e3 100644
--- a/libp2p/NodeTable.h
+++ b/libp2p/NodeTable.h
@@ -36,16 +36,20 @@ namespace p2p
  */
 struct NodeIPEndpoint
 {
+	NodeIPEndpoint(): udp(bi::udp::endpoint()), tcp(bi::tcp::endpoint()) {}
 	NodeIPEndpoint(bi::udp::endpoint _udp): udp(_udp) {}
 	NodeIPEndpoint(bi::tcp::endpoint _tcp): tcp(_tcp) {}
 	NodeIPEndpoint(bi::udp::endpoint _udp, bi::tcp::endpoint _tcp): udp(_udp), tcp(_tcp) {}
 
 	bi::udp::endpoint udp;
 	bi::tcp::endpoint tcp;
+	
+	operator bool() const { return udp.address().is_unspecified() && tcp.address().is_unspecified(); }
 };
 
 struct Node
 {
+	Node(): endpoint(NodeIPEndpoint()) {};
 	Node(Public _pubk, NodeIPEndpoint _ip, bool _required = false): id(_pubk), endpoint(_ip), required(_required) {}
 	Node(Public _pubk, bi::udp::endpoint _udp, bool _required = false): Node(_pubk, NodeIPEndpoint(_udp), _required) {}
 	
@@ -59,6 +63,8 @@ struct Node
 	
 	/// If true, node will not be removed from Node list.
 	bool required = false;
+	
+	operator bool() const { return (bool)id; }
 };
 
 
@@ -151,7 +157,7 @@ public:
 	std::list<NodeId> nodes() const;
 	std::list<NodeEntry> state() const;
 	
-	NodeEntry operator[](NodeId _id);
+	Node operator[](NodeId _id);
 	
 protected:
 	struct NodeBucket
diff --git a/test/peer.cpp b/test/peer.cpp
index 70d03e9bf..d13ea97f3 100644
--- a/test/peer.cpp
+++ b/test/peer.cpp
@@ -55,7 +55,7 @@ int peerTest(int argc, char** argv)
 	{
 		this_thread::sleep_for(chrono::milliseconds(100));
 		if (!(i % 10))
-			ph.pingAll();
+			ph.keepAlivePeers();
 	}
 
 	return 0;