diff --git a/src/native/libs/System.Native/extra_libs.cmake b/src/native/libs/System.Native/extra_libs.cmake
index 8a3fa8a1006abd..b9d18b61a429bc 100644
--- a/src/native/libs/System.Native/extra_libs.cmake
+++ b/src/native/libs/System.Native/extra_libs.cmake
@@ -9,7 +9,7 @@ macro(append_extra_system_libs NativeLibsExtra)
     elseif (CLR_CMAKE_TARGET_OPENBSD)
         list(APPEND ${NativeLibsExtra} pthread)
     elseif (CLR_CMAKE_TARGET_SUNOS)
-        list(APPEND ${NativeLibsExtra} socket)
+        list(APPEND ${NativeLibsExtra} socket nsl)
     elseif (CLR_CMAKE_TARGET_HAIKU)
         list (APPEND ${NativeLibsExtra} network bsd)
     endif ()
diff --git a/src/native/libs/System.Native/pal_networking.c b/src/native/libs/System.Native/pal_networking.c
index 3b460d4c4e8296..1c2ad8643bca27 100644
--- a/src/native/libs/System.Native/pal_networking.c
+++ b/src/native/libs/System.Native/pal_networking.c
@@ -52,6 +52,10 @@
 #include <stdio.h>
 #endif
 #include <unistd.h>
+#if defined(TARGET_SUNOS) && HAVE_GETDOMAINNAME
+// SunOS has getdomainname in libnsl but no header declaration
+extern int getdomainname(char *name, int namelen);
+#endif
 #ifdef HAVE_PWD_H
 #include <pwd.h>
 #endif
diff --git a/src/native/libs/configure.cmake b/src/native/libs/configure.cmake
index 5b39e586216f98..726cad88f48d09 100644
--- a/src/native/libs/configure.cmake
+++ b/src/native/libs/configure.cmake
@@ -977,29 +977,44 @@ check_symbol_exists(
     "unistd.h;sys/types.h;sys/socket.h"
     HAVE_GETPEEREID)
 
-check_symbol_exists(
-    getdomainname
-    unistd.h
-    HAVE_GETDOMAINNAME)
+set (PREVIOUS_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
+if (CLR_CMAKE_TARGET_SUNOS)
+    # On SunOS, getdomainname is in libnsl but not declared in any header
+    set(CMAKE_REQUIRED_LIBRARIES socket nsl)
+    check_function_exists(
+        getdomainname
+        HAVE_GETDOMAINNAME)
+else()
+    check_symbol_exists(
+        getdomainname
+        unistd.h
+        HAVE_GETDOMAINNAME)
+endif()
 
-# getdomainname on OSX takes an 'int' instead of a 'size_t'
-# check if compiling with 'size_t' would cause a warning
-set (PREVIOUS_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
-set (CMAKE_REQUIRED_FLAGS "-Werror -Weverything")
-check_c_source_compiles(
-    "
-    #include <unistd.h>
-    int main(void)
-    {
-        size_t namelen = 20;
-        char name[20];
-        int dummy = getdomainname(name, namelen);
-        (void)dummy;
-        return 0;
-    }
-    "
-    HAVE_GETDOMAINNAME_SIZET)
-set (CMAKE_REQUIRED_FLAGS ${PREVIOUS_CMAKE_REQUIRED_FLAGS})
+# Some platforms (e.g. macOS, SunOS) define getdomainname with an 'int' length parameter
+# Check whether using 'size_t' for the length parameter would cause a warning
+if (CLR_CMAKE_TARGET_SUNOS)
+    # SunOS uses int, not size_t
+    set (HAVE_GETDOMAINNAME_SIZET 0)
+else()
+    set (PREVIOUS_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
+    set (CMAKE_REQUIRED_FLAGS "-Werror -Weverything")
+    check_c_source_compiles(
+        "
+        #include <unistd.h>
+        int main(void)
+        {
+            size_t namelen = 20;
+            char name[20];
+            int dummy = getdomainname(name, namelen);
+            (void)dummy;
+            return 0;
+        }
+        "
+        HAVE_GETDOMAINNAME_SIZET)
+    set (CMAKE_REQUIRED_FLAGS ${PREVIOUS_CMAKE_REQUIRED_FLAGS})
+endif()
+set (CMAKE_REQUIRED_LIBRARIES ${PREVIOUS_CMAKE_REQUIRED_LIBRARIES})
 
 set (PREVIOUS_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
 if (HAVE_SYS_INOTIFY_H AND (CLR_CMAKE_TARGET_FREEBSD OR CLR_CMAKE_TARGET_OPENBSD))