diff --git a/engine/common/common.h b/engine/common/common.h
index 10e1b06c..0aa2ebbc 100644
--- a/engine/common/common.h
+++ b/engine/common/common.h
@@ -876,6 +876,10 @@ void NET_InitMasters( void );
 void NET_SaveMasters( void );
 qboolean NET_SendToMasters( netsrc_t sock, size_t len, const void *data );
 qboolean NET_IsMasterAdr( netadr_t adr );
+void NET_MasterHeartbeat( void );
+void NET_MasterClear( void );
+void NET_MasterShutdown( void );
+qboolean NET_GetMaster( netadr_t from, uint *challenge, double *last_heartbeat );
 
 #ifdef REF_DLL
 #error "common.h in ref_dll"
diff --git a/engine/common/masterlist.c b/engine/common/masterlist.c
index bb2edcc8..0900918b 100644
--- a/engine/common/masterlist.c
+++ b/engine/common/masterlist.c
@@ -14,22 +14,49 @@ GNU General Public License for more details.
 */
 #include "common.h"
 #include "netchan.h"
+#include "server.h"
 
 typedef struct master_s
 {
 	struct master_s *next;
-	qboolean sent;
+	qboolean sent; // TODO: get rid of this internal state
 	qboolean save;
 	string address;
 	netadr_t adr; // temporary, rewritten after each send
+
+	uint heartbeat_challenge;
+	double last_heartbeat;
 } master_t;
 
-struct masterlist_s
+static struct masterlist_s
 {
 	master_t *list;
 	qboolean modified;
 } ml;
 
+static CVAR_DEFINE_AUTO( sv_verbose_heartbeats, "0", 0, "print every heartbeat to console" );
+
+#define HEARTBEAT_SECONDS	((sv_nat.value > 0.0f) ? 60.0f : 300.0f)  	// 1 or 5 minutes
+
+/*
+========================
+NET_GetMasterHostByName
+========================
+*/
+static net_gai_state_t NET_GetMasterHostByName( master_t *m )
+{
+	net_gai_state_t res = NET_StringToAdrNB( m->address, &m->adr );
+
+	if( res == NET_EAI_OK )
+		return res;
+
+	m->adr.type = NA_UNUSED;
+	if( res == NET_EAI_NONAME )
+		Con_Reportf( "Can't resolve adr: %s\n", m->address );
+
+	return res;
+}
+
 /*
 ========================
 NET_SendToMasters
@@ -45,65 +72,176 @@ qboolean NET_SendToMasters( netsrc_t sock, size_t len, const void *data )
 
 	for( list = ml.list; list; list = list->next )
 	{
-		int res;
-
 		if( list->sent )
 			continue;
 
-		res = NET_StringToAdrNB( list->address, &list->adr );
-
-		if( !res )
+		switch( NET_GetMasterHostByName( list ))
 		{
-			Con_Reportf( "Can't resolve adr: %s\n", list->address );
+		case NET_EAI_AGAIN:
+			list->sent = false;
+			wait = true;
+			break;
+		case NET_EAI_NONAME:
 			list->sent = true;
-			list->adr.type = NA_UNUSED;
-			continue;
+			break;
+		case NET_EAI_OK:
+			list->sent = true;
+			NET_SendPacket( sock, len, data, list->adr );
+			break;
 		}
+	}
 
-		if( res == 2 )
-		{
+	if( !wait )
+	{
+		// reset sent state
+		for( list = ml.list; list; list = list->next )
 			list->sent = false;
-			list->adr.type = NA_UNUSED;
-			wait = true;
-			continue;
-		}
+	}
+
+	return wait;
+}
+
+/*
+========================
+NET_AnnounceToMaster
+
+========================
+*/
+static void NET_AnnounceToMaster( master_t *m )
+{
+	sizebuf_t msg;
+	char buf[16];
+
+	m->heartbeat_challenge = COM_RandomLong( 0, INT_MAX );
 
-		list->sent = true;
+	MSG_Init( &msg, "Master Join", buf, sizeof( buf ));
+	MSG_WriteBytes( &msg, "q\xFF", 2 );
+	MSG_WriteDword( &msg, m->heartbeat_challenge );
 
-		NET_SendPacket( sock, len, data, list->adr );
+	NET_SendPacket( NS_SERVER, MSG_GetNumBytesWritten( &msg ), MSG_GetBuf( &msg ), m->adr );
+
+	if( sv_verbose_heartbeats.value )
+	{
+		Con_Printf( S_NOTE "sent heartbeat to %s (%s, 0x%x)\n",
+			m->address, NET_AdrToString( m->adr ), m->heartbeat_challenge );
 	}
+}
 
-	if( !wait )
+/*
+========================
+NET_AnnounceToMaster
+
+========================
+*/
+void NET_MasterClear( void )
+{
+	master_t *m;
+
+	for( m = ml.list; m; m = m->next )
+		m->last_heartbeat = MAX_HEARTBEAT;
+}
+
+/*
+========================
+NET_MasterHeartbeat
+
+========================
+*/
+void NET_MasterHeartbeat( void )
+{
+	master_t *m;
+
+	if(( !public_server.value && !sv_nat.value ) || svs.maxclients == 1 )
+		return; // only public servers send heartbeats
+
+	for( m = ml.list; m; m = m->next )
 	{
-		list = ml.list;
+		if( host.realtime - m->last_heartbeat < HEARTBEAT_SECONDS )
+			continue;
 
-		while( list )
+		switch( NET_GetMasterHostByName( m ))
 		{
-			list->sent = false;
-			list = list->next;
+		case NET_EAI_AGAIN:
+			m->last_heartbeat = MAX_HEARTBEAT; // retry on next frame
+			if( sv_verbose_heartbeats.value )
+				Con_Printf( S_NOTE "delay heartbeat to next frame until %s resolves\n", m->address );
+
+			break;
+		case NET_EAI_NONAME:
+			m->last_heartbeat = host.realtime; // try to resolve again on next heartbeat
+			break;
+		case NET_EAI_OK:
+			m->last_heartbeat = host.realtime;
+			NET_AnnounceToMaster( m );
+			break;
 		}
 	}
+}
 
-	return wait;
+/*
+=================
+NET_MasterShutdown
+
+Informs all masters that this server is going down
+(ignored by master servers in current implementation)
+=================
+*/
+void NET_MasterShutdown( void )
+{
+	NET_Config( true, false ); // allow remote
+	while( NET_SendToMasters( NS_SERVER, 2, "\x62\x0A" ));
 }
 
+
 /*
 ========================
-NET_IsMasterAdr
+NET_GetMasterFromAdr
 
 ========================
 */
-qboolean NET_IsMasterAdr( netadr_t adr )
+static master_t *NET_GetMasterFromAdr( netadr_t adr )
 {
 	master_t *master;
 
 	for( master = ml.list; master; master = master->next )
 	{
 		if( NET_CompareAdr( adr, master->adr ))
-			return true;
+			return master;
 	}
 
-	return false;
+	return NULL;
+}
+
+
+/*
+========================
+NET_GetMaster
+========================
+*/
+qboolean NET_GetMaster( netadr_t from, uint *challenge, double *last_heartbeat )
+{
+	master_t *m;
+
+	m = NET_GetMasterFromAdr( from );
+
+	if( m )
+	{
+		*challenge = m->heartbeat_challenge;
+		*last_heartbeat = m->last_heartbeat;
+	}
+
+	return m != NULL;
+}
+
+/*
+========================
+NET_IsMasterAdr
+
+========================
+*/
+qboolean NET_IsMasterAdr( netadr_t adr )
+{
+	return NET_GetMasterFromAdr( adr ) != NULL;
 }
 
 /*
@@ -277,6 +415,8 @@ void NET_InitMasters( void )
 	Cmd_AddRestrictedCommand( "clearmasters", NET_ClearMasters_f, "clear masterserver list" );
 	Cmd_AddCommand( "listmasters", NET_ListMasters_f, "list masterservers" );
 
+	Cvar_RegisterVariable( &sv_verbose_heartbeats );
+
 	// keep main master always there
 	NET_AddMaster( MASTERSERVER_ADR, false );
 	NET_LoadMasters( );
diff --git a/engine/server/server.h b/engine/server/server.h
index a62f9e4c..6c59ba62 100644
--- a/engine/server/server.h
+++ b/engine/server/server.h
@@ -374,9 +374,7 @@ typedef struct
 	entity_state_t	*baselines;		// [GI->max_edicts]
 	entity_state_t	*static_entities;		// [MAX_STATIC_ENTITIES];
 
-	double		last_heartbeat;
 	challenge_t	challenges[MAX_CHALLENGES];	// to prevent invalid IPs from connecting
-	uint		heartbeat_challenge;
 } server_static_t;
 
 //=============================================================================
@@ -444,6 +442,7 @@ extern convar_t		skill;
 extern convar_t		coop;
 extern convar_t		sv_cheats;
 extern convar_t		public_server;
+extern convar_t		sv_nat;
 
 extern	convar_t		*sv_pausable;		// allows pause in multiplayer
 extern	convar_t		*sv_check_errors;
diff --git a/engine/server/sv_client.c b/engine/server/sv_client.c
index e4c1e8e5..9a4e0171 100644
--- a/engine/server/sv_client.c
+++ b/engine/server/sv_client.c
@@ -475,7 +475,7 @@ void SV_ConnectClient( netadr_t from )
 	Log_Printf( "\"%s<%i><%i><>\" connected, address \"%s\"\n", newcl->name, newcl->userid, i, NET_AdrToString( newcl->netchan.remote_address ));
 
 	if( count == 1 || count == svs.maxclients )
-		svs.last_heartbeat = MAX_HEARTBEAT;
+		NET_MasterClear();
 }
 
 /*
@@ -542,7 +542,7 @@ edict_t *SV_FakeConnect( const char *netname )
 	cl->state = cs_spawned;
 
 	if( count == 1 || count == svs.maxclients )
-		svs.last_heartbeat = MAX_HEARTBEAT;
+		NET_MasterClear();
 
 	return cl->edict;
 }
@@ -619,7 +619,7 @@ void SV_DropClient( sv_client_t *cl, qboolean crash )
 	}
 
 	if( i == svs.maxclients )
-		svs.last_heartbeat = MAX_HEARTBEAT;
+		NET_MasterClear();
 }
 
 /*
@@ -3116,7 +3116,7 @@ void SV_ConnectionlessPacket( netadr_t from, sizebuf_t *msg )
 	else if( !Q_strcmp( pcmd, "s" )) SV_AddToMaster( from, msg );
 	else if( !Q_strcmp( pcmd, "T" "Source" )) SV_TSourceEngineQuery( from );
 	else if( !Q_strcmp( pcmd, "i" )) NET_SendPacket( NS_SERVER, 5, "\xFF\xFF\xFF\xFFj", from ); // A2A_PING
-	else if( !Q_strcmp( pcmd, "c" ) && Cvar_VariableInteger( "sv_nat" ) && NET_IsMasterAdr( from ))
+	else if( !Q_strcmp( pcmd, "c" ) && sv_nat.value && NET_IsMasterAdr( from ))
 	{
 		netadr_t to;
 		if( NET_StringToAdr( Cmd_Argv( 1 ), &to ) && !NET_IsReservedAdr( to ))
diff --git a/engine/server/sv_cmds.c b/engine/server/sv_cmds.c
index 1eb81d22..b2bcf469 100644
--- a/engine/server/sv_cmds.c
+++ b/engine/server/sv_cmds.c
@@ -749,9 +749,9 @@ void SV_ConSay_f( void )
 SV_Heartbeat_f
 ==================
 */
-void SV_Heartbeat_f( void )
+static void SV_Heartbeat_f( void )
 {
-	svs.last_heartbeat = MAX_HEARTBEAT;
+	NET_MasterClear();
 }
 
 /*
diff --git a/engine/server/sv_init.c b/engine/server/sv_init.c
index 9f9efdca..3ac2043d 100644
--- a/engine/server/sv_init.c
+++ b/engine/server/sv_init.c
@@ -1012,7 +1012,7 @@ qboolean SV_SpawnServer( const char *mapname, const char *startspot, qboolean ba
 	}
 
 	// heartbeats will always be sent to the id master
-	svs.last_heartbeat = MAX_HEARTBEAT; // send immediately
+	NET_MasterClear();
 
 	// get actual movevars
 	SV_UpdateMovevars( true );
diff --git a/engine/server/sv_main.c b/engine/server/sv_main.c
index 50e8ee36..59923634 100644
--- a/engine/server/sv_main.c
+++ b/engine/server/sv_main.c
@@ -18,8 +18,6 @@ GNU General Public License for more details.
 #include "net_encode.h"
 #include "platform/platform.h"
 
-#define HEARTBEAT_SECONDS	((sv_nat.value > 0.0f) ? 60.0f : 300.0f)  	// 1 or 5 minutes
-
 // server cvars
 CVAR_DEFINE_AUTO( sv_lan, "0", 0, "server is a lan server ( no heartbeat, no authentication, no non-class C addresses, 9999.0 rate, etc." );
 CVAR_DEFINE_AUTO( sv_lan_rate, "20000.0", 0, "rate for lan server" );
@@ -142,8 +140,6 @@ convar_t	*sv_allow_mouse;
 convar_t	*sv_allow_joystick;
 convar_t	*sv_allow_vr;
 
-static void Master_Heartbeat( void );
-
 //============================================================================
 /*
 ================
@@ -668,7 +664,7 @@ void Host_ServerFrame( void )
 	Platform_UpdateStatusLine ();
 
 	// send a heartbeat to the master if needed
-	Master_Heartbeat ();
+	NET_MasterHeartbeat ();
 }
 
 /*
@@ -683,68 +679,6 @@ void Host_SetServerState( int state )
 }
 
 //============================================================================
-
-/*
-=================
-Master_Add
-=================
-*/
-static void Master_Add( void )
-{
-	sizebuf_t msg;
-	char buf[16];
-	uint challenge;
-
-	NET_Config( true, false ); // allow remote
-
-	svs.heartbeat_challenge = challenge = COM_RandomLong( 0, INT_MAX );
-
-	MSG_Init( &msg, "Master Join", buf, sizeof( buf ));
-	MSG_WriteBytes( &msg, "q\xFF", 2 );
-	MSG_WriteDword( &msg, challenge );
-
-	if( NET_SendToMasters( NS_SERVER, MSG_GetNumBytesWritten( &msg ), MSG_GetBuf( &msg )))
-		svs.last_heartbeat = MAX_HEARTBEAT;
-}
-
-/*
-================
-Master_Heartbeat
-
-Send a message to the master every few minutes to
-let it know we are alive, and log information
-================
-*/
-static void Master_Heartbeat( void )
-{
-	if(( !public_server.value && !sv_nat.value ) || svs.maxclients == 1 )
-		return; // only public servers send heartbeats
-
-	// check for time wraparound
-	if( svs.last_heartbeat > host.realtime )
-		svs.last_heartbeat = host.realtime;
-
-	if(( host.realtime - svs.last_heartbeat ) < HEARTBEAT_SECONDS )
-		return; // not time to send yet
-
-	svs.last_heartbeat = host.realtime;
-
-	Master_Add();
-}
-
-/*
-=================
-Master_Shutdown
-
-Informs all masters that this server is going down
-=================
-*/
-static void Master_Shutdown( void )
-{
-	NET_Config( true, false ); // allow remote
-	while( NET_SendToMasters( NS_SERVER, 2, "\x62\x0A" ));
-}
-
 /*
 =================
 SV_AddToMaster
@@ -755,18 +689,19 @@ Master will validate challenge and this server to public list
 */
 void SV_AddToMaster( netadr_t from, sizebuf_t *msg )
 {
-	uint	challenge, challenge2;
+	uint	challenge, challenge2, heartbeat_challenge;
 	char	s[MAX_INFO_STRING] = "0\n"; // skip 2 bytes of header
 	int	clients, bots;
+	double last_heartbeat;
 	const int len = sizeof( s );
 
-	if( !NET_IsMasterAdr( from ))
+	if( !NET_GetMaster( from, &heartbeat_challenge, &last_heartbeat ))
 	{
 		Con_Printf( S_WARN "unexpected master server info query packet from %s\n", NET_AdrToString( from ));
 		return;
 	}
 
-	if( svs.last_heartbeat + sv_master_response_timeout.value < host.realtime )
+	if( last_heartbeat + sv_master_response_timeout.value < host.realtime )
 	{
 		Con_Printf( S_WARN "unexpected master server info query packet (too late? try increasing sv_master_response_timeout value)\n");
 		return;
@@ -775,7 +710,7 @@ void SV_AddToMaster( netadr_t from, sizebuf_t *msg )
 	challenge = MSG_ReadDword( msg );
 	challenge2 = MSG_ReadDword( msg );
 
-	if( challenge2 != svs.heartbeat_challenge )
+	if( challenge2 != heartbeat_challenge )
 	{
 		Con_Printf( S_WARN "unexpected master server info query packet (wrong challenge!)\n" );
 		return;
@@ -1114,7 +1049,7 @@ void SV_Shutdown( const char *finalmsg )
 		SV_FinalMessage( finalmsg, false );
 
 	if( public_server.value && svs.maxclients != 1 )
-		Master_Shutdown();
+		NET_MasterShutdown();
 
 	NET_Config( false, false );
 	SV_UnloadProgs ();