diff --git a/build.yaml b/build.yaml
index 198467bf5ade45e4b6b0f2bd434467ef0ec6adb0..a84ef6b88f170e08ef50ff9729857dd52ef7d002 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 90580c5fad8fbd446abedb29464079f009216361..669524859f203bcb535d9652ff940e36421eabf8 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 749dde8a0be72db814b550f99ac3fb93ef61ebf1..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
@@ -38,8 +38,8 @@
 #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/nameser.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"
 
@@ -358,9 +358,6 @@ static grpc_ares_request *grpc_dns_lookup_ares_impl(
     grpc_ares_request_ref(r);
     char *service_name;
     gpr_asprintf(&service_name, "_grpclb._tcp.%s", host);
-    // see: RFC 1035, section 3.2.4. CLASS values
-    const int ns_c_in = 1; // internet
-    const int ns_t_srv = 33; // SRV record (RFC 2782)
     ares_query(*channel, service_name, ns_c_in, ns_t_srv, on_srv_query_done_cb,
                r);
     gpr_free(service_name);
diff --git a/src/core/lib/iomgr/nameser.h b/src/core/lib/iomgr/nameser.h
index 8edee50138a36fe0462475fb896d3475fc64a6cb..daed6de518cefa1eb864e9846f8591159236b26a 100644
--- a/src/core/lib/iomgr/nameser.h
+++ b/src/core/lib/iomgr/nameser.h
@@ -28,75 +28,75 @@
 #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_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_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 */
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 24e7ff2b7bc44ce4cd98f11695951eb5549c2389..dcd7c7d1f3d913e121355ffe6ce81531a23bad23 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -7744,6 +7744,7 @@
       "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", 
@@ -7909,6 +7910,7 @@
       "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>