diff --git a/contrib/discover.py b/contrib/discover.py
index a41d264c1..a008a5dd1 100755
--- a/contrib/discover.py
+++ b/contrib/discover.py
@@ -2,9 +2,13 @@
 import sys
 import subprocess
 import socket
-from xml.dom.minidom import parseString
+from xml.dom.minidom import parse
 
-service_templates = {
+if len(sys.argv) < 2:
+    print "Syntax: %s <xml-file> [<xml-file> ...]" % (sys.argv[0])
+    sys.exit(1)
+
+tcp_service_templates = {
   'ssh': 'ssh',
   'http': 'http_ip',
   'https': 'https_ip',
@@ -12,34 +16,52 @@ service_templates = {
   'ssmtp': 'ssmtp'
 }
 
-# Expects XML output from 'nmap -oX'
-dom = parseString(sys.stdin.read())
+udp_service_templates = {
+  'ntp': 'ntp_time',
+  'snmp': 'snmp-uptime'
+}
 
-def processHost(host):
-    for element in host.getElementsByTagName("status"):
-        if element.getAttribute("state") != "up":
-            return
+hosts = {}
 
-    for element in host.getElementsByTagName("address"):
-        if not element.getAttribute("addrtype") in [ "ipv4", "ipv6" ]:
+def process_host(host_element):
+    global hosts
+
+    status = "down"
+
+    for status_element in host_element.getElementsByTagName("status"):
+        status = status_element.getAttribute("state")
+
+    if status != "up":
+        return
+
+    for address_element in host_element.getElementsByTagName("address"):
+        if not address_element.getAttribute("addrtype") in [ "ipv4", "ipv6" ]:
             continue
-        
-        address = element.getAttribute("addr")
+
+        address = address_element.getAttribute("addr")
         break
 
-    hostname = address
+    name = address
 
-    for element in host.getElementsByTagName("hostname"):
-        hostname = element.getAttribute("name")
+    for hostname_element in host_element.getElementsByTagName("hostname"):
+        name = hostname_element.getAttribute("name")
 
-    print "object Host \"%s\" inherits \"itl-host\" {" % (hostname)
-    print "\tmacros = {"
-    print "\t\taddress = \"%s\"" % (address)
-    print "\t},"
+    try:
+        services = hosts[name]["services"]
+    except:
+        services = {}
 
-    for element in host.getElementsByTagName("port"):
-        port = int(element.getAttribute("portid"))
-        protocol = element.getAttribute("protocol")
+    for port_element in host_element.getElementsByTagName("port"):
+        state = "closed"
+
+        for state_element in port_element.getElementsByTagName("state"):
+            state = state_element.getAttribute("state")
+
+        if state != "open":
+            continue
+
+        port = int(port_element.getAttribute("portid"))
+        protocol = port_element.getAttribute("protocol")
 
         try:
             serv = socket.getservbyport(port, protocol)
@@ -47,23 +69,51 @@ def processHost(host):
             serv = str(port)
 
         try:
-            template = service_templates[serv]
+            if protocol == "tcp":
+                template = tcp_service_templates[serv]
+            elif protocol == "udp":
+                template = udp_service_templates[serv]
+            else:
+                raise "Unknown protocol."
         except:
             template = protocol
 
+        if template == "udp":
+            continue
+
+        services[serv] = { "template": template, "port": port }
+
+    hosts[name] = { "name": name, "address": address, "services": services }
+
+def print_host(host):
+    print "object Host \"%s\" inherits \"discovered-host\" {" % (host["name"])
+    print "\tmacros = {"
+    print "\t\taddress = \"%s\"" % (host["address"])
+    print "\t},"
+
+    for serv, service in host["services"].iteritems():
         print ""
         print "\tservices[\"%s\"] = {" % (serv)
-        print "\t\ttemplates = { \"%s\" }," % (template)
+        print "\t\ttemplates = { \"%s\" }," % (service["template"])
         print ""
         print "\t\tmacros = {"
-        print "\t\t\tport = %s" % (port)
+        print "\t\t\tport = %s" % (service["port"])
         print "\t\t}"
         print "\t},"
 
     print "}"
     print ""
 
-print "#include <itl/itl.conf>"
 
-for host in dom.getElementsByTagName("host"):
-    processHost(host)
+print "#include <itl/itl.conf>"
+print ""
+
+for arg in sys.argv[1:]:
+    # Expects XML output from 'nmap -oX'
+    dom = parse(arg)
+
+    for host in dom.getElementsByTagName("host"):
+        process_host(host)
+
+for host in hosts.values():
+    print_host(host)
diff --git a/itl/service-common.conf b/itl/service-common.conf
index e1fc5eef5..625955194 100644
--- a/itl/service-common.conf
+++ b/itl/service-common.conf
@@ -210,3 +210,22 @@ template Service "load" inherits "plugin-service" {
 		cload15 = 4.0
 	}
 }
+
+template Service "snmp" inherits "plugin-service" {
+	check_command = {
+		"$plugindir$/check_snmp",
+		"-H", "$address$",
+		"-o", "$oid$",
+		"-C", "$community$"
+	},
+
+	macros = {
+		community = "public"
+	}
+}
+
+template Service "snmp-uptime" inherits "snmp" {
+	macros += {
+		oid = "1.3.6.1.2.1.1.3.0"
+	}
+}
diff --git a/lib/base/dynamicobject.cpp b/lib/base/dynamicobject.cpp
index f3c0e4cce..d0693d64f 100644
--- a/lib/base/dynamicobject.cpp
+++ b/lib/base/dynamicobject.cpp
@@ -431,6 +431,9 @@ ScriptTask::Ptr DynamicObject::MakeMethodTask(const String& method,
 
 	methods = m_Methods;
 
+	if (!methods)
+		return ScriptTask::Ptr();
+
 	String funcName = methods->Get(method);
 
 	if (funcName.IsEmpty())
diff --git a/lib/icinga/macroprocessor.cpp b/lib/icinga/macroprocessor.cpp
index ec9514982..7d469661f 100644
--- a/lib/icinga/macroprocessor.cpp
+++ b/lib/icinga/macroprocessor.cpp
@@ -64,7 +64,7 @@ String MacroProcessor::InternalResolveMacros(const String& str, const Dictionary
 		pos_second = result.FindFirstOf("$", pos_first + 1);
 
 		if (pos_second == String::NPos)
-			BOOST_THROW_EXCEPTION(runtime_error("Closing $ not found in macro format String."));
+			BOOST_THROW_EXCEPTION(runtime_error("Closing $ not found in macro format string."));
 
 		String name = result.SubStr(pos_first + 1, pos_second - pos_first - 1);