diff --git a/src/daemon/name-server.cpp b/src/daemon/name-server.cpp
new file mode 100644
index 0000000..072e889
--- /dev/null
+++ b/src/daemon/name-server.cpp
@@ -0,0 +1,224 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014, Regents of the University of California.
+ *
+ * This file is part of NDNS (Named Data Networking Domain Name Service).
+ * See AUTHORS.md for complete list of NDNS authors and contributors.
+ *
+ * NDNS is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NDNS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NDNS, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "name-server.hpp"
+#include "logger.hpp"
+#include "clients/response.hpp"
+#include <ndn-cxx/encoding/encoding-buffer.hpp>
+
+namespace ndn {
+namespace ndns {
+NDNS_LOG_INIT("NameServer")
+
+const time::milliseconds NAME_SERVER_DEFAULT_CONTENT_FRESHNESS(4000);
+
+NameServer::NameServer(const Name& zoneName, const Name& certName, Face& face, DbMgr& dbMgr,
+                       KeyChain& keyChain, Validator& validator)
+  : m_zone(zoneName)
+  , m_dbMgr(dbMgr)
+  , m_ndnsPrefix(zoneName)
+  , m_keyPrefix(zoneName)
+  , m_certName(certName)
+  , m_contentFreshness(NAME_SERVER_DEFAULT_CONTENT_FRESHNESS)
+  , m_face(face)
+  , m_keyChain(keyChain)
+  , m_validator(validator)
+{
+  if (!m_keyChain.doesCertificateExist(m_certName)) {
+    NDNS_LOG_FATAL("Certificate: " << m_certName << " does not exist");
+    throw Error("certificate does not exist in the KeyChain: " + m_certName.toUri());
+  }
+
+  m_dbMgr.find(m_zone);
+
+  if (m_zone.getId() == 0) {
+    NDNS_LOG_FATAL("m_zone does not exist: " << zoneName);
+    throw Error("Zone " + zoneName.toUri() + " does not exist in the database");
+  }
+
+  m_ndnsPrefix.append(ndns::label::NDNS_ITERATIVE_QUERY);
+  m_keyPrefix.append(ndns::label::NDNS_CERT_QUERY);
+
+  m_face.setInterestFilter(m_ndnsPrefix,
+                           bind(&NameServer::onInterest, this, _1, _2),
+                           bind(&NameServer::onRegisterFailed, this, _1, _2)
+                           );
+
+  m_face.setInterestFilter(m_keyPrefix,
+                           bind(&NameServer::onInterest, this, _1, _2),
+                           bind(&NameServer::onRegisterFailed, this, _1, _2)
+                           );
+
+  NDNS_LOG_INFO("Zone: " << m_zone.getName() << " binds "
+                << "Prefix: " << m_ndnsPrefix << " and " << m_keyPrefix
+                << " with Certificate: " << m_certName
+                );
+}
+
+void
+NameServer::onInterest(const Name& prefix, const Interest& interest)
+{
+  label::MatchResult re;
+  if (!label::matchName(interest, "", m_zone.getName(), re))
+    return;
+
+  if (re.rrType == ndns::label::NDNS_UPDATE_LABEL) {
+    this->handleUpdate(prefix, interest, re); // NDNS Update
+  }
+  else {
+    this->handleQuery(prefix, interest, re);  // NDNS Iterative query
+  }
+}
+
+void
+NameServer::handleQuery(const Name& prefix, const Interest& interest, const label::MatchResult& re)
+{
+  Rrset rrset(&m_zone);
+  rrset.setLabel(re.rrLabel);
+  rrset.setType(re.rrType);
+
+  NDNS_LOG_TRACE("query record: " << interest.getName());
+
+  if (m_dbMgr.find(rrset)) {
+    // find the record: NDNS-RESP, NDNS-AUTH, NDNS-RAW, or NDNS-NACK
+    shared_ptr<Data> answer = make_shared<Data>(rrset.getData());
+    NDNS_LOG_TRACE("answer query with existing Data: " << answer->getName());
+    m_face.put(*answer);
+  }
+  else {
+    // no record, construct NACK
+    Block block = nonNegativeIntegerBlock(::ndn::ndns::tlv::NdnsType, NDNS_NACK);
+    MetaInfo info;
+    info.addAppMetaInfo(block);
+    info.setFreshnessPeriod(this->getContentFreshness());
+    Name name = interest.getName();
+    name.appendVersion();
+    shared_ptr<Data> answer = make_shared<Data>(name);
+    answer->setMetaInfo(info);
+
+    m_keyChain.sign(*answer, m_certName);
+    NDNS_LOG_TRACE("answer query with NDNS-NACK: " << answer->getName());
+    m_face.put(*answer);
+  }
+}
+
+void
+NameServer::handleUpdate(const Name& prefix, const Interest& interest, const label::MatchResult& re)
+{
+  if (re.rrLabel.size() == 1) {
+    // for current, we only allow Update message contains one Data, and ignore others
+    auto it = re.rrLabel.begin();
+    shared_ptr<Data> data;
+    try {
+      // blockFromValue may throw exception, which should not lead to failure of name server
+      const Block& block = it->blockFromValue();
+      data = make_shared<Data>(block);
+    }
+    catch (std::exception& e) {
+      NDNS_LOG_WARN("exception when getting update info: " << e.what());
+      return;
+    }
+    m_validator.validate(*data,
+                         bind(&NameServer::doUpdate, this, interest.shared_from_this(), data),
+                         [this] (const shared_ptr<const Data>& data, const std::string& msg) {
+                           NDNS_LOG_WARN("Ignoring update that did not pass the verification");
+                         });
+  }
+}
+
+void
+NameServer::onRegisterFailed(const ndn::Name& prefix, const std::string& reason)
+{
+  NDNS_LOG_FATAL("fail to register prefix=" << prefix << ". Due to: " << reason);
+  throw Error("zone " + m_zone.getName().toUri() + " register prefix: " +
+              prefix.toUri() + " fails. due to: " + reason);
+}
+
+void
+NameServer::doUpdate(const shared_ptr<const Interest>& interest,
+                     const shared_ptr<const Data>& data)
+{
+  label::MatchResult re;
+  try {
+    if (!label::matchName(*data, "", m_zone.getName(), re))
+      return;
+  }
+  catch (std::exception& e) {
+    NDNS_LOG_INFO("Error while name/certificate matching: " << e.what());
+  }
+
+  Rrset rrset(&m_zone);
+  rrset.setLabel(re.rrLabel);
+  rrset.setType(re.rrType);
+
+  Block ndnsType = nonNegativeIntegerBlock(::ndn::ndns::tlv::NdnsType, NDNS_RESP);
+  MetaInfo info;
+  info.addAppMetaInfo(ndnsType);
+  info.setFreshnessPeriod(this->getContentFreshness());
+  Name name = interest->getName();
+  name.appendVersion();
+  shared_ptr<Data> answer = make_shared<Data>(name);
+  answer->setMetaInfo(info);
+
+  Block blk(ndn::ndns::tlv::RrData);
+  try {
+    if (m_dbMgr.find(rrset)) {
+      const name::Component& newVersion = re.version;
+      if (newVersion > rrset.getVersion()) {
+        // update existing record
+        rrset.setVersion(newVersion);
+        rrset.setData(data->wireEncode());
+        m_dbMgr.update(rrset);
+        blk.push_back(nonNegativeIntegerBlock(ndn::ndns::tlv::UpdateReturnCode, UPDATE_OK));
+        blk.encode(); // must
+        answer->setContent(blk);
+        NDNS_LOG_TRACE("replace old record and answer update with UPDATE_OK");
+      }
+      else {
+        blk.push_back(nonNegativeIntegerBlock(ndn::ndns::tlv::UpdateReturnCode, UPDATE_FAILURE));
+        blk.encode();
+        answer->setContent(blk);
+        NDNS_LOG_TRACE("answer update with UPDATE_FAILURE");
+      }
+    }
+    else {
+      // insert new record
+      rrset.setVersion(re.version);
+      rrset.setData(data->wireEncode());
+      rrset.setTtl(m_zone.getTtl());
+      m_dbMgr.insert(rrset);
+      blk.push_back(nonNegativeIntegerBlock(ndn::ndns::tlv::UpdateReturnCode, UPDATE_OK));
+      blk.encode();
+      answer->setContent(blk);
+      NDNS_LOG_TRACE("insert new record and answer update with UPDATE_OK");
+    }
+  }
+  catch (std::exception& e) {
+    blk.push_back(nonNegativeIntegerBlock(ndn::ndns::tlv::UpdateReturnCode, UPDATE_FAILURE));
+    blk.encode(); // must
+    answer->setContent(blk);
+    NDNS_LOG_INFO("Error processing the update: " << e.what());
+    NDNS_LOG_TRACE("exception happens and answer update with UPDATE_FAILURE");
+  }
+  m_keyChain.sign(*answer, m_certName);
+  m_face.put(*answer);
+}
+
+} // namespace ndns
+} // namespace ndn