diff --git a/lg.py b/lg.py
index 70af2af..8d113ab 100644
--- a/lg.py
+++ b/lg.py
@@ -53,13 +53,16 @@ memcache_expiration = int(app.config.get("MEMCACHE_EXPIRATION", "1296000")) # 1
 mc = memcache.Client([memcache_server])
 
 def get_asn_from_as(n):
-    asn_zone = app.config.get("ASN_ZONE", "asn.cymru.com")
-    try:
-        data = resolve("AS%s.%s" % (n, asn_zone) ,"TXT").replace("'","").replace('"','')
-    except:
-        return " "*5
-    return [ field.strip() for field in data.split("|") ]
-
+    asn_zone = app.config.get("ASN_ZONE", False)
+    # don't generate spurious (and potentially slow) lookups if ASN_ZONE not defined in config
+    if asn_zone:
+        try:
+            data = resolve("AS%s.%s" % (n, asn_zone) ,"TXT").replace("'","").replace('"','')
+        except:
+            return False
+        return [ field.strip() for field in data.split("|") ]
+    else:
+        return False
 
 def add_links(text):
     """Browser a string and replace ipv4, ipv6, as number, with a
@@ -403,9 +406,13 @@ def get_as_name(_as):
     name = mc.get(str('lg_%s' % _as))
     if not name:
         app.logger.info("asn for as %s not found in memcache", _as)
-        name = get_asn_from_as(_as)[-1].replace(" ","\r",1)
-        if name:
+        asn_result = get_asn_from_as(_as)
+        if asn_result:
+            name = asn_result[-1].replace(" ","\r",1)
             mc.set(str("lg_%s" % _as), str(name), memcache_expiration)
+        else:
+            return "AS%s" % (_as)
+
     return "AS%s | %s" % (_as, name)
 
 
@@ -560,18 +567,20 @@ def build_as_tree_from_raw_bird_ouput(host, proto, text):
     for line in text:
         line = line.strip()
 
-        expr = re.search(r'(.*)via\s+([0-9a-fA-F:\.]+)\s+on.*\[(\w+)\s+', line)
+        expr = re.search(r'(.*)unicast\s+\[(\w+)\s+', line)
         if expr:
+            if expr.group(1).strip():
+                net_dest = expr.group(1).strip()
+            peer_protocol_name = expr.group(2).strip()
+
+        expr2 = re.search(r'via\s+([0-9a-fA-F:\.]+)', line)
+        if expr2:
             if path:
                 path.append(net_dest)
                 paths.append(path)
                 path = None
 
-            if expr.group(1).strip():
-                net_dest = expr.group(1).strip()
-
-            peer_ip = expr.group(2).strip()
-            peer_protocol_name = expr.group(3).strip()
+            peer_ip = expr2.group(1).strip()
             # Check if via line is a internal route
             for rt_host, rt_ips in app.config["ROUTER_IP"].iteritems():
                 # Special case for internal routing
@@ -583,15 +592,15 @@ def build_as_tree_from_raw_bird_ouput(host, proto, text):
                 path = [ peer_protocol_name ]
 #                path = ["%s\r%s" % (peer_protocol_name, get_as_name(get_as_number_from_protocol_name(host, proto, peer_protocol_name)))]
         
-        expr2 = re.search(r'(.*)unreachable\s+\[(\w+)\s+', line)
-        if expr2:
+        expr3 = re.search(r'(.*)unreachable\s+\[(\w+)\s+', line)
+        if expr3:
             if path:
                 path.append(net_dest)
                 paths.append(path)
                 path = None
 
-            if expr2.group(1).strip():
-                net_dest = expr2.group(1).strip()
+            if expr3.group(1).strip():
+                net_dest = expr3.group(1).strip()
 
         if line.startswith("BGP.as_path:"):
             path.extend(line.replace("BGP.as_path:", "").strip().split(" "))