diff --git a/DnsServerCore/Dns/Zones/CacheZone.cs b/DnsServerCore/Dns/Zones/CacheZone.cs
index 27174b3e..820ce6dc 100644
--- a/DnsServerCore/Dns/Zones/CacheZone.cs
+++ b/DnsServerCore/Dns/Zones/CacheZone.cs
@@ -1,6 +1,6 @@
 /*
 Technitium DNS Server
-Copyright (C) 2021  Shreyas Zare (shreyas@technitium.com)
+Copyright (C) 2022  Shreyas Zare (shreyas@technitium.com)
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -19,7 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 using System;
 using System.Collections.Generic;
-using TechnitiumLibrary.IO;
+using TechnitiumLibrary;
 using TechnitiumLibrary.Net.Dns;
 using TechnitiumLibrary.Net.Dns.ResourceRecords;
 
@@ -37,14 +37,14 @@ namespace DnsServerCore.Dns.Zones
 
         #region private
 
-        private static IReadOnlyList<DnsResourceRecord> ValidateRRSet(DnsResourceRecordType type, IReadOnlyList<DnsResourceRecord> records, bool serveStale, bool checkForSpecialCacheRecord)
+        private static IReadOnlyList<DnsResourceRecord> ValidateRRSet(DnsResourceRecordType type, IReadOnlyList<DnsResourceRecord> records, bool serveStale, bool skipSpecialCacheRecord)
         {
             foreach (DnsResourceRecord record in records)
             {
                 if (record.IsExpired(serveStale))
                     return Array.Empty<DnsResourceRecord>(); //RR Set is expired
 
-                if (checkForSpecialCacheRecord && (record.RDATA is DnsCache.DnsSpecialCacheRecord))
+                if (skipSpecialCacheRecord && (record.RDATA is DnsCache.DnsSpecialCacheRecord))
                     return Array.Empty<DnsResourceRecord>(); //RR Set is special cache record
             }
 
@@ -69,13 +69,13 @@ namespace DnsServerCore.Dns.Zones
 
         public void SetRecords(DnsResourceRecordType type, IReadOnlyList<DnsResourceRecord> records, bool serveStale)
         {
-            bool isFailureRecord = (records.Count > 0) && (records[0].RDATA is DnsCache.DnsSpecialCacheRecord splRecord) && splRecord.IsFailure;
+            bool isFailureRecord = (records.Count > 0) && (records[0].RDATA is DnsCache.DnsSpecialCacheRecord splRecord) && (splRecord.Type == DnsCache.DnsSpecialCacheRecordType.FailureCache);
             if (isFailureRecord)
             {
                 //call trying to cache failure record
                 if (_entries.TryGetValue(type, out IReadOnlyList<DnsResourceRecord> existingRecords))
                 {
-                    if ((existingRecords.Count > 0) && !(existingRecords[0].RDATA is DnsCache.DnsSpecialCacheRecord existingSplRecord && existingSplRecord.IsFailure) && !DnsResourceRecord.IsRRSetExpired(existingRecords, serveStale))
+                    if ((existingRecords.Count > 0) && !(existingRecords[0].RDATA is DnsCache.DnsSpecialCacheRecord existingSplRecord && (existingSplRecord.Type == DnsCache.DnsSpecialCacheRecordType.FailureCache)) && !DnsResourceRecord.IsRRSetExpired(existingRecords, serveStale))
                         return; //skip to avoid overwriting a useful record with a failure record
                 }
             }
@@ -92,6 +92,7 @@ namespace DnsServerCore.Dns.Zones
                     case DnsResourceRecordType.CNAME:
                     case DnsResourceRecordType.SOA:
                     case DnsResourceRecordType.NS:
+                    case DnsResourceRecordType.DS:
                         //do nothing
                         break;
 
@@ -121,32 +122,63 @@ namespace DnsServerCore.Dns.Zones
             }
         }
 
-        public IReadOnlyList<DnsResourceRecord> QueryRecords(DnsResourceRecordType type, bool serveStale, bool checkForSpecialCacheRecord)
+        public IReadOnlyList<DnsResourceRecord> QueryRecords(DnsResourceRecordType type, bool serveStale, bool skipSpecialCacheRecord)
         {
-            //check for CNAME
-            if (_entries.TryGetValue(DnsResourceRecordType.CNAME, out IReadOnlyList<DnsResourceRecord> existingCNAMERecords))
+            switch (type)
             {
-                IReadOnlyList<DnsResourceRecord> rrset = ValidateRRSet(type, existingCNAMERecords, serveStale, checkForSpecialCacheRecord);
-                if (rrset.Count > 0)
-                {
-                    if ((type == DnsResourceRecordType.CNAME) || (rrset[0].RDATA is DnsCNAMERecord))
-                        return rrset;
-                }
+                case DnsResourceRecordType.DS:
+                    {
+                        //since some zones have CNAME at apex so no CNAME lookup for DS queries!
+                        if (_entries.TryGetValue(type, out IReadOnlyList<DnsResourceRecord> existingRecords))
+                            return ValidateRRSet(type, existingRecords, serveStale, skipSpecialCacheRecord);
+                    }
+                    break;
+
+                case DnsResourceRecordType.SOA:
+                case DnsResourceRecordType.DNSKEY:
+                    {
+                        //since some zones have CNAME at apex!
+                        if (_entries.TryGetValue(type, out IReadOnlyList<DnsResourceRecord> existingRecords))
+                            return ValidateRRSet(type, existingRecords, serveStale, skipSpecialCacheRecord);
+
+                        if (_entries.TryGetValue(DnsResourceRecordType.CNAME, out IReadOnlyList<DnsResourceRecord> existingCNAMERecords))
+                        {
+                            IReadOnlyList<DnsResourceRecord> rrset = ValidateRRSet(type, existingCNAMERecords, serveStale, skipSpecialCacheRecord);
+                            if (rrset.Count > 0)
+                            {
+                                if ((type == DnsResourceRecordType.CNAME) || (rrset[0].RDATA is DnsCNAMERecord))
+                                    return rrset;
+                            }
+                        }
+                    }
+                    break;
+
+                case DnsResourceRecordType.ANY:
+                    List<DnsResourceRecord> anyRecords = new List<DnsResourceRecord>();
+
+                    foreach (KeyValuePair<DnsResourceRecordType, IReadOnlyList<DnsResourceRecord>> entry in _entries)
+                        anyRecords.AddRange(ValidateRRSet(type, entry.Value, serveStale, true));
+
+                    return anyRecords;
+
+                default:
+                    {
+                        if (_entries.TryGetValue(DnsResourceRecordType.CNAME, out IReadOnlyList<DnsResourceRecord> existingCNAMERecords))
+                        {
+                            IReadOnlyList<DnsResourceRecord> rrset = ValidateRRSet(type, existingCNAMERecords, serveStale, skipSpecialCacheRecord);
+                            if (rrset.Count > 0)
+                            {
+                                if ((type == DnsResourceRecordType.CNAME) || (rrset[0].RDATA is DnsCNAMERecord))
+                                    return rrset;
+                            }
+                        }
+
+                        if (_entries.TryGetValue(type, out IReadOnlyList<DnsResourceRecord> existingRecords))
+                            return ValidateRRSet(type, existingRecords, serveStale, skipSpecialCacheRecord);
+                    }
+                    break;
             }
 
-            if (type == DnsResourceRecordType.ANY)
-            {
-                List<DnsResourceRecord> anyRecords = new List<DnsResourceRecord>();
-
-                foreach (KeyValuePair<DnsResourceRecordType, IReadOnlyList<DnsResourceRecord>> entry in _entries)
-                    anyRecords.AddRange(ValidateRRSet(type, entry.Value, serveStale, true));
-
-                return anyRecords;
-            }
-
-            if (_entries.TryGetValue(type, out IReadOnlyList<DnsResourceRecord> existingRecords))
-                return ValidateRRSet(type, existingRecords, serveStale, checkForSpecialCacheRecord);
-
             return Array.Empty<DnsResourceRecord>();
         }