diff --git a/BUILD b/BUILD
index 6dcc76eb7aa4093041d5208cb0887116129f87b5..6552d5879e60ebfd3bb7c1cbbc2c6a0d1382579d 100644
--- a/BUILD
+++ b/BUILD
@@ -725,6 +725,7 @@ grpc_cc_library(
         "src/core/lib/iomgr/is_epollexclusive_available.h",
         "src/core/lib/iomgr/load_file.h",
         "src/core/lib/iomgr/lockfree_event.h",
+        "src/core/lib/iomgr/nameser.h",
         "src/core/lib/iomgr/network_status_tracker.h",
         "src/core/lib/iomgr/polling_entity.h",
         "src/core/lib/iomgr/pollset.h",
diff --git a/build.yaml b/build.yaml
index 9c2504af71fa56ba5b0975b24f1429b00657ac01..52ffbc6c58235754f47e48ff071409e811fa6d62 100644
--- a/build.yaml
+++ b/build.yaml
@@ -218,6 +218,7 @@ filegroups:
   - src/core/lib/iomgr/is_epollexclusive_available.h
   - src/core/lib/iomgr/load_file.h
   - src/core/lib/iomgr/lockfree_event.h
+  - src/core/lib/iomgr/nameser.h
   - src/core/lib/iomgr/network_status_tracker.h
   - src/core/lib/iomgr/polling_entity.h
   - src/core/lib/iomgr/pollset.h
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 202af58919201ab6ac117ee5fe7040efe6a2050d..332d331d621ed51148ab8826c5903f40e19a7da0 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -281,6 +281,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/is_epollexclusive_available.h',
                       'src/core/lib/iomgr/load_file.h',
                       'src/core/lib/iomgr/lockfree_event.h',
+                      'src/core/lib/iomgr/nameser.h',
                       'src/core/lib/iomgr/network_status_tracker.h',
                       'src/core/lib/iomgr/polling_entity.h',
                       'src/core/lib/iomgr/pollset.h',
@@ -766,6 +767,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/is_epollexclusive_available.h',
                               'src/core/lib/iomgr/load_file.h',
                               'src/core/lib/iomgr/lockfree_event.h',
+                              'src/core/lib/iomgr/nameser.h',
                               'src/core/lib/iomgr/network_status_tracker.h',
                               'src/core/lib/iomgr/polling_entity.h',
                               'src/core/lib/iomgr/pollset.h',
diff --git a/grpc.gemspec b/grpc.gemspec
index a166839888c7e46b97392b0f340d6bd33eb4b666..fee406892cd80f418a3f5d9bf7a7ba51993151d4 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -213,6 +213,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/is_epollexclusive_available.h )
   s.files += %w( src/core/lib/iomgr/load_file.h )
   s.files += %w( src/core/lib/iomgr/lockfree_event.h )
+  s.files += %w( src/core/lib/iomgr/nameser.h )
   s.files += %w( src/core/lib/iomgr/network_status_tracker.h )
   s.files += %w( src/core/lib/iomgr/polling_entity.h )
   s.files += %w( src/core/lib/iomgr/pollset.h )
diff --git a/package.xml b/package.xml
index b31514b99ff9c6b7521ebb764a5a497b0c14723b..04ab3d2e325950827f67e9ff7b9a4893654ccacb 100644
--- a/package.xml
+++ b/package.xml
@@ -227,6 +227,7 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/is_epollexclusive_available.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/load_file.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/lockfree_event.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/nameser.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/network_status_tracker.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/polling_entity.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset.h" role="src" />
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
index 9065e33613331ae305d915afb2aecd737fbd0985..6ec3790a5fec9d3d6f915ab54e861a89341a0e41 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
@@ -33,13 +33,13 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 #include <grpc/support/useful.h>
-#include <nameser.h>
 
 #include "src/core/ext/filters/client_channel/parse_address.h"
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/nameser.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/support/string.h"
 
diff --git a/src/core/lib/iomgr/nameser.h b/src/core/lib/iomgr/nameser.h
new file mode 100644
index 0000000000000000000000000000000000000000..daed6de518cefa1eb864e9846f8591159236b26a
--- /dev/null
+++ b/src/core/lib/iomgr/nameser.h
@@ -0,0 +1,104 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_NAMESER_H
+#define GRPC_CORE_LIB_IOMGR_NAMESER_H
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_HAVE_ARPA_NAMESER
+
+#include <arpa/nameser.h>
+
+#else /* GRPC_HAVE_ARPA_NAMESER */
+
+typedef enum __ns_class {
+  ns_c_invalid = 0, /* Cookie. */
+  ns_c_in = 1,      /* Internet. */
+  ns_c_2 = 2,       /* unallocated/unsupported. */
+  ns_c_chaos = 3,   /* MIT Chaos-net. */
+  ns_c_hs = 4,      /* MIT Hesiod. */
+  /* Query class values which do not appear in resource records */
+  ns_c_none = 254, /* for prereq. sections in update requests */
+  ns_c_any = 255,  /* Wildcard match. */
+  ns_c_max = 65536
+} ns_class;
+
+typedef enum __ns_type {
+  ns_t_invalid = 0,   /* Cookie. */
+  ns_t_a = 1,         /* Host address. */
+  ns_t_ns = 2,        /* Authoritative server. */
+  ns_t_md = 3,        /* Mail destination. */
+  ns_t_mf = 4,        /* Mail forwarder. */
+  ns_t_cname = 5,     /* Canonical name. */
+  ns_t_soa = 6,       /* Start of authority zone. */
+  ns_t_mb = 7,        /* Mailbox domain name. */
+  ns_t_mg = 8,        /* Mail group member. */
+  ns_t_mr = 9,        /* Mail rename name. */
+  ns_t_null = 10,     /* Null resource record. */
+  ns_t_wks = 11,      /* Well known service. */
+  ns_t_ptr = 12,      /* Domain name pointer. */
+  ns_t_hinfo = 13,    /* Host information. */
+  ns_t_minfo = 14,    /* Mailbox information. */
+  ns_t_mx = 15,       /* Mail routing information. */
+  ns_t_txt = 16,      /* Text strings. */
+  ns_t_rp = 17,       /* Responsible person. */
+  ns_t_afsdb = 18,    /* AFS cell database. */
+  ns_t_x25 = 19,      /* X_25 calling address. */
+  ns_t_isdn = 20,     /* ISDN calling address. */
+  ns_t_rt = 21,       /* Router. */
+  ns_t_nsap = 22,     /* NSAP address. */
+  ns_t_nsap_ptr = 23, /* Reverse NSAP lookup (deprecated). */
+  ns_t_sig = 24,      /* Security signature. */
+  ns_t_key = 25,      /* Security key. */
+  ns_t_px = 26,       /* X.400 mail mapping. */
+  ns_t_gpos = 27,     /* Geographical position (withdrawn). */
+  ns_t_aaaa = 28,     /* Ip6 Address. */
+  ns_t_loc = 29,      /* Location Information. */
+  ns_t_nxt = 30,      /* Next domain (security). */
+  ns_t_eid = 31,      /* Endpoint identifier. */
+  ns_t_nimloc = 32,   /* Nimrod Locator. */
+  ns_t_srv = 33,      /* Server Selection. */
+  ns_t_atma = 34,     /* ATM Address */
+  ns_t_naptr = 35,    /* Naming Authority PoinTeR */
+  ns_t_kx = 36,       /* Key Exchange */
+  ns_t_cert = 37,     /* Certification record */
+  ns_t_a6 = 38,       /* IPv6 address (deprecates AAAA) */
+  ns_t_dname = 39,    /* Non-terminal DNAME (for IPv6) */
+  ns_t_sink = 40,     /* Kitchen sink (experimentatl) */
+  ns_t_opt = 41,      /* EDNS0 option (meta-RR) */
+  ns_t_apl = 42,      /* Address prefix list (RFC3123) */
+  ns_t_ds = 43,       /* Delegation Signer (RFC4034) */
+  ns_t_sshfp = 44,    /* SSH Key Fingerprint (RFC4255) */
+  ns_t_rrsig = 46,    /* Resource Record Signature (RFC4034) */
+  ns_t_nsec = 47,     /* Next Secure (RFC4034) */
+  ns_t_dnskey = 48,   /* DNS Public Key (RFC4034) */
+  ns_t_tkey = 249,    /* Transaction key */
+  ns_t_tsig = 250,    /* Transaction signature. */
+  ns_t_ixfr = 251,    /* Incremental zone transfer. */
+  ns_t_axfr = 252,    /* Transfer zone of authority. */
+  ns_t_mailb = 253,   /* Transfer mailbox records. */
+  ns_t_maila = 254,   /* Transfer mail agent records. */
+  ns_t_any = 255,     /* Wildcard match. */
+  ns_t_zxfr = 256,    /* BIND-specific, nonstandard. */
+  ns_t_max = 65536
+} ns_type;
+
+#endif /* GRPC_HAVE_ARPA_NAMESER */
+
+#endif /* GRPC_CORE_LIB_IOMGR_NAMESER_H */
diff --git a/src/core/lib/iomgr/port.h b/src/core/lib/iomgr/port.h
index f5d15b48506c72b9cdf517f6f0bf40d6e4757422..c12058f890b118d08fe5767f75f793ded0488deb 100644
--- a/src/core/lib/iomgr/port.h
+++ b/src/core/lib/iomgr/port.h
@@ -24,6 +24,7 @@
 #if defined(GRPC_UV)
 // Do nothing
 #elif defined(GPR_MANYLINUX1)
+#define GRPC_HAVE_ARPA_NAMESER 1
 #define GRPC_HAVE_IFADDRS 1
 #define GRPC_HAVE_IPV6_RECVPKTINFO 1
 #define GRPC_HAVE_IP_PKTINFO 1
@@ -51,6 +52,7 @@
 #define GRPC_POSIX_WAKEUP_FD 1
 #define GRPC_TIMER_USE_GENERIC 1
 #elif defined(GPR_LINUX)
+#define GRPC_HAVE_ARPA_NAMESER 1
 #define GRPC_HAVE_IFADDRS 1
 #define GRPC_HAVE_IPV6_RECVPKTINFO 1
 #define GRPC_HAVE_IP_PKTINFO 1
@@ -82,6 +84,7 @@
 #define GRPC_POSIX_SOCKETUTILS
 #endif
 #elif defined(GPR_APPLE)
+#define GRPC_HAVE_ARPA_NAMESER 1
 #define GRPC_HAVE_IFADDRS 1
 #define GRPC_HAVE_SO_NOSIGPIPE 1
 #define GRPC_HAVE_UNIX_SOCKET 1
@@ -93,6 +96,7 @@
 #define GRPC_POSIX_WAKEUP_FD 1
 #define GRPC_TIMER_USE_GENERIC 1
 #elif defined(GPR_FREEBSD)
+#define GRPC_HAVE_ARPA_NAMESER 1
 #define GRPC_HAVE_IFADDRS 1
 #define GRPC_HAVE_IPV6_RECVPKTINFO 1
 #define GRPC_HAVE_SO_NOSIGPIPE 1
@@ -104,6 +108,7 @@
 #define GRPC_POSIX_WAKEUP_FD 1
 #define GRPC_TIMER_USE_GENERIC 1
 #elif defined(GPR_NACL)
+#define GRPC_HAVE_ARPA_NAMESER 1
 #define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index b747da3a6761ee3f580897d1e516c156f4abe30d..6e7f92717d6255b15ea1abcfb093971cfb4f12b8 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -1131,6 +1131,7 @@ src/core/lib/iomgr/load_file.c \
 src/core/lib/iomgr/load_file.h \
 src/core/lib/iomgr/lockfree_event.c \
 src/core/lib/iomgr/lockfree_event.h \
+src/core/lib/iomgr/nameser.h \
 src/core/lib/iomgr/network_status_tracker.c \
 src/core/lib/iomgr/network_status_tracker.h \
 src/core/lib/iomgr/polling_entity.c \
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index aa76fc047fb000d7c9888d12b8f9f1c2a5d573ef..8d57ea2ede69b4744e96346a1c6ca64ed7e9dac7 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -7761,6 +7761,7 @@
       "src/core/lib/iomgr/is_epollexclusive_available.h", 
       "src/core/lib/iomgr/load_file.h", 
       "src/core/lib/iomgr/lockfree_event.h", 
+      "src/core/lib/iomgr/nameser.h", 
       "src/core/lib/iomgr/network_status_tracker.h", 
       "src/core/lib/iomgr/polling_entity.h", 
       "src/core/lib/iomgr/pollset.h", 
@@ -7926,6 +7927,7 @@
       "src/core/lib/iomgr/load_file.h", 
       "src/core/lib/iomgr/lockfree_event.c", 
       "src/core/lib/iomgr/lockfree_event.h", 
+      "src/core/lib/iomgr/nameser.h", 
       "src/core/lib/iomgr/network_status_tracker.c", 
       "src/core/lib/iomgr/network_status_tracker.h", 
       "src/core/lib/iomgr/polling_entity.c", 
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj b/vsprojects/vcxproj/grpc/grpc.vcxproj
index 57c0ac7bc4e63adbbaedf1b0fa8238b62b262783..ff2e26e0af0b97b9ca043d909e909b3d3d5cab49 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj
@@ -338,6 +338,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\is_epollexclusive_available.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\nameser.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
index e9bb52defa666a9600f83d7809213db54aaa0031..70824a51b89304b68c67d2dc0af767fa4d844a1d 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
@@ -971,6 +971,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\nameser.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
index 64bf54e557d354f418acac0c2ca8b4dc85b1b3eb..13d56d58a8e2f84958a42853bdc23116c687b3c9 100644
--- a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
+++ b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
@@ -233,6 +233,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\is_epollexclusive_available.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\nameser.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
diff --git a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
index 35fd87a4c589e77be6d25246ccf228ae174d998e..fb7197fa95228ff704c6d99597e2df23284c6824 100644
--- a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
@@ -695,6 +695,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\nameser.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
index 4ed59780a446b771818a70f667f2d86772821e82..b9e0c896e1ad5c3f043849268e5d25719193d104 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
@@ -328,6 +328,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\is_epollexclusive_available.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\nameser.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
index 2c3319beae8772c92e4e47aafa4ebacf2d7fb987..ed3384d5d20f93acafd62c22c9c4858c50f20c65 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
@@ -878,6 +878,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\nameser.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>