Index: src/protocol/http/org/apache/jmeter/protocol/http/control/DNSCacheManager.java
===================================================================
--- src/protocol/http/org/apache/jmeter/protocol/http/control/DNSCacheManager.java	(Revision 1803896)
+++ src/protocol/http/org/apache/jmeter/protocol/http/control/DNSCacheManager.java	(Arbeitskopie)
@@ -217,7 +217,10 @@
                 List<InetAddress> addresses = new ArrayList<>();
                 for (String address : Arrays.asList(entry.getAddress().split("\\s*,\\s*"))) {
                     try {
-                        addresses.addAll(Arrays.asList(requestLookup(address)));
+                        final InetAddress[] requestLookup = requestLookup(address);
+                        if (requestLookup != null) {
+                            addresses.addAll(Arrays.asList(requestLookup));
+                        }
                     } catch (UnknownHostException e) {
                         log.warn("Couldn't resolve static address {} for host {}", address, host, e);
                     }
@@ -239,25 +242,35 @@
             ExtendedResolver extendedResolver = getResolver();
             if (extendedResolver != null) {
                 if(extendedResolver.getResolvers().length > 0) {
-                    try {
-                        Lookup lookup = new Lookup(host, Type.A);
-                        lookup.setCache(lookupCache);
-                        if (timeoutMs > 0) {
-                            resolver.setTimeout(timeoutMs / 1000, timeoutMs % 1000);
+                    for (Resolver currentResolver : extendedResolver
+                            .getResolvers()) {
+                        log.debug("Use custom resolver: {}", currentResolver);
+                        try {
+                            Lookup lookup = new Lookup(host, Type.A);
+                            lookup.setCache(lookupCache);
+                            if (timeoutMs > 0) {
+                                currentResolver.setTimeout(timeoutMs / 1000,
+                                        timeoutMs % 1000);
+                            }
+                            lookup.setResolver(currentResolver);
+                            Record[] records = lookup.run();
+                            if (records == null || records.length == 0) {
+                                log.debug("Lookup of host {} failed with {}",
+                                        host, currentResolver);
+                                continue;
+                            }
+                            addresses = new InetAddress[records.length];
+                            for (int i = 0; i < records.length; i++) {
+                                addresses[i] = ((ARecord) records[i])
+                                        .getAddress();
+                            }
+                        } catch (TextParseException tpe) {
+                            log.debug("Failed to create Lookup object: " + tpe);
                         }
-                        lookup.setResolver(resolver);
-                        Record[] records = lookup.run();
-                        if (records == null || records.length == 0) {
-                            throw new UnknownHostException("Failed to resolve host name: " + host);
-                        }
-                        addresses = new InetAddress[records.length];
-                        for (int i = 0; i < records.length; i++) {
-                            addresses[i] = ((ARecord) records[i]).getAddress();
-                        }
-                    } catch (TextParseException tpe) {
-                        log.debug("Failed to create Lookup object: " + tpe);
+                        return addresses;
                     }
-                    return addresses;
+                    throw new UnknownHostException(
+                            "Failed to resolve host name: " + host);
                 }
             } else {
                 throw new UnknownHostException("Could not resolve host:"+host