diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index d162f4aaf0d9..61a75365ca54 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -186,6 +186,8 @@ Improvements
 * SOLR-17607: SolrJ CloudSolrClient configured with HTTP URLs will no longer eagerly connect to
   anything. (David Smiley)
 
+* SOLR-17685: Simplify bin/solr scripts by no longer SOLR_TOOL_HOST variable in favour of existing SOLR_HOST ENV variable. (Eric Pugh, Houston Putnam)
+
 Optimizations
 ---------------------
 * SOLR-17578: Remove ZkController internal core supplier, for slightly faster reconnection after Zookeeper session loss. (Pierre Salagnac)
diff --git a/solr/bin/solr b/solr/bin/solr
index 09784892f90f..2d53e0bc8cec 100755
--- a/solr/bin/solr
+++ b/solr/bin/solr
@@ -356,10 +356,6 @@ fi
 # This looks strange, but it is to avoid extra spaces when we have only one of the values set
 AUTHC_OPTS="${AUTHC_OPTS:-}${SOLR_AUTHENTICATION_OPTS:+ $SOLR_AUTHENTICATION_OPTS}"
 
-# Set the SOLR_TOOL_HOST variable for use when connecting to a running Solr instance
-SOLR_TOOL_HOST="${SOLR_HOST:-localhost}"
-export SOLR_TOOL_HOST
-
 function print_usage() {
   CMD="${1:-}"
   ERROR_MSG="${2:-}"
@@ -601,6 +597,10 @@ if [[ "$SCRIPT_CMD" == "auth" ]]; then
     exit 1
   fi
 
+  if [ -n "${AUTH_PORT}" ]; then
+    export SOLR_PORT="${AUTH_PORT}"
+  fi
+  
   if [ -z "${SOLR_HOME:-}" ]; then
     SOLR_HOME="$SOLR_SERVER_DIR/solr"
   elif [[ $SOLR_HOME != /* ]]; then
@@ -612,22 +612,11 @@ if [[ "$SCRIPT_CMD" == "auth" ]]; then
     fi
   fi
 
-  if [ -z "${AUTH_PORT:-}" ]; then
-    for ID in $(ps auxww | grep java | grep start\.jar | awk '{print $2}' | sort -r)
-      do
-        port=$(jetty_port "$ID")
-        if [ "$port" != "" ]; then
-          AUTH_PORT=$port
-          break
-        fi
-      done
-  fi
-
-  run_tool auth $@ --solr-url "$SOLR_URL_SCHEME://$SOLR_TOOL_HOST:${AUTH_PORT:-8983}" --auth-conf-dir "$SOLR_HOME" "--solr-include-file" "$SOLR_INCLUDE"
+  run_tool auth $@ --auth-conf-dir "$SOLR_HOME" "--solr-include-file" "$SOLR_INCLUDE"
   exit $?
 fi
 
-# at this point all tools that have a custom run process, like "status" and "auth" have been run and exited.
+# at this point the only tool that has a custom run process, "auth" has been run and exited.
 # Unless a command is one of the ones in the if clause below, we will just run it with the default run_tool function and then exit.
 if [ "$SCRIPT_CMD" != "start" ] && [ "$SCRIPT_CMD" != "stop" ] && [ "$SCRIPT_CMD" != "restart" ]; then
   # hand off the command to the SolrCLI and let it handle the option parsing and validation
diff --git a/solr/bin/solr.cmd b/solr/bin/solr.cmd
index 3b971b68dfc2..43928a5a6ae7 100755
--- a/solr/bin/solr.cmd
+++ b/solr/bin/solr.cmd
@@ -240,12 +240,6 @@ IF DEFINED SOLR_AUTHENTICATION_CLIENT_BUILDER (
 )
 set "AUTHC_OPTS=%AUTHC_CLIENT_BUILDER_ARG% %SOLR_AUTHENTICATION_OPTS%"
 
-REM Set the SOLR_TOOL_HOST variable for use when connecting to a running Solr instance
-IF NOT "%SOLR_HOST%"=="" (
-  set "SOLR_TOOL_HOST=%SOLR_HOST%"
-) ELSE (
-  set "SOLR_TOOL_HOST=localhost"
-)
 IF "%SOLR_JETTY_HOST%"=="" (
   set "SOLR_JETTY_HOST=127.0.0.1"
 )
@@ -1175,7 +1169,7 @@ IF "%FG%"=="1" (
   "%JAVA%" %SOLR_SSL_OPTS% %AUTHC_OPTS% %SOLR_ZK_CREDS_AND_ACLS% %SOLR_TOOL_OPTS% -Dsolr.install.dir="%SOLR_TIP%" -Dsolr.default.confdir="%DEFAULT_CONFDIR%"^
     -Dlog4j.configurationFile="file:///%DEFAULT_SERVER_DIR%\resources\log4j2-console.xml" ^
     -classpath "%DEFAULT_SERVER_DIR%\solr-webapp\webapp\WEB-INF\lib\*;%DEFAULT_SERVER_DIR%\lib\ext\*" ^
-    org.apache.solr.cli.SolrCLI status --max-wait-secs !SOLR_START_WAIT! --solr-url !SOLR_URL_SCHEME!://%SOLR_TOOL_HOST%:%SOLR_PORT%
+    org.apache.solr.cli.SolrCLI status --max-wait-secs !SOLR_START_WAIT!
   IF NOT "!ERRORLEVEL!"=="0" (
       set "SCRIPT_ERROR=Solr did not start or was not reachable. Check the logs for errors."
       goto err
@@ -1220,22 +1214,14 @@ IF NOT EXIST "%SOLR_HOME%\" (
   )
 )
 
-if "!AUTH_PORT!"=="" (
-  for /f "usebackq" %%i in (`dir /b "%SOLR_TIP%\bin" ^| findstr /i "^solr-.*\.port$"`) do (
-    set SOME_SOLR_PORT=
-    For /F "Delims=" %%J In ('type "%SOLR_TIP%\bin\%%i"') do set SOME_SOLR_PORT=%%~J
-    if NOT "!SOME_SOLR_PORT!"=="" (
-      for /f "tokens=2,5" %%j in ('netstat -aon ^| find "TCP " ^| find ":0 " ^| find ":!SOME_SOLR_PORT! "') do (
-        IF NOT "%%k"=="0" set AUTH_PORT=!SOME_SOLR_PORT!
-      )
-    )
-  )
+IF DEFINED AUTH_PORT (
+  set "SOLR_PORT=%AUTH_PORT%"
 )
+
 "%JAVA%" %SOLR_SSL_OPTS% %AUTHC_OPTS% %SOLR_ZK_CREDS_AND_ACLS% %SOLR_TOOL_OPTS% -Dsolr.install.dir="%SOLR_TIP%" ^
     -Dlog4j.configurationFile="file:///%DEFAULT_SERVER_DIR%\resources\log4j2-console.xml" ^
     -classpath "%DEFAULT_SERVER_DIR%\solr-webapp\webapp\WEB-INF\lib\*;%DEFAULT_SERVER_DIR%\lib\ext\*" ^
-    org.apache.solr.cli.SolrCLI auth %AUTH_PARAMS% --solr-include-file "%SOLR_INCLUDE%" --auth-conf-dir "%SOLR_HOME%" ^
-    --solr-url !SOLR_URL_SCHEME!://%SOLR_TOOL_HOST%:!AUTH_PORT!
+    org.apache.solr.cli.SolrCLI auth %AUTH_PARAMS% --solr-include-file "%SOLR_INCLUDE%" --auth-conf-dir "%SOLR_HOME%"
 goto done
 
 :err
diff --git a/solr/core/src/java/org/apache/solr/cli/AuthTool.java b/solr/core/src/java/org/apache/solr/cli/AuthTool.java
index 6a71164a03d8..c1fd6098e6c0 100644
--- a/solr/core/src/java/org/apache/solr/cli/AuthTool.java
+++ b/solr/core/src/java/org/apache/solr/cli/AuthTool.java
@@ -75,8 +75,10 @@ public class AuthTool extends ToolBase {
           .longOpt("solr-include-file")
           .hasArg()
           .argName("FILE")
+          .required()
           .desc(
-              "The Solr include file which contains overridable environment variables for configuring Solr configurations.")
+              "The Solr include file which contains overridable environment variables for configuring Solr configurations.  Defaults to solr.in."
+                  + (CLIUtils.isWindows() ? ".cmd" : ".sh"))
           .build();
 
   private static final Option UPDATE_INCLUDE_FILE_OPTION =
@@ -96,7 +98,7 @@ public class AuthTool extends ToolBase {
           .argName("FILE")
           .required()
           .desc(
-              "This is where any authentication related configuration files, if any, would be placed.")
+              "This is where any authentication related configuration files, if any, would be placed.  Defaults to $SOLR_HOME.")
           .build();
 
   public AuthTool() {
diff --git a/solr/core/src/java/org/apache/solr/cli/CLIUtils.java b/solr/core/src/java/org/apache/solr/cli/CLIUtils.java
index 93fb1403957b..de41c34d6dd9 100644
--- a/solr/core/src/java/org/apache/solr/cli/CLIUtils.java
+++ b/solr/core/src/java/org/apache/solr/cli/CLIUtils.java
@@ -36,6 +36,7 @@
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import org.apache.commons.cli.CommandLine;
+import org.apache.commons.exec.OS;
 import org.apache.solr.client.solrj.SolrClient;
 import org.apache.solr.client.solrj.SolrRequest;
 import org.apache.solr.client.solrj.SolrServerException;
@@ -70,7 +71,7 @@ private CLIUtils() {}
   public static String getDefaultSolrUrl() {
     // note that ENV_VAR syntax (and the env vars too) are mapped to env.var sys props
     String scheme = EnvUtils.getProperty("solr.url.scheme", "http");
-    String host = EnvUtils.getProperty("solr.tool.host", "localhost");
+    String host = EnvUtils.getProperty("solr.host", "localhost");
     String port = EnvUtils.getProperty("jetty.port", "8983"); // from SOLR_PORT env
     return String.format(Locale.ROOT, "%s://%s:%s", scheme.toLowerCase(Locale.ROOT), host, port);
   }
@@ -346,4 +347,8 @@ public static Path getConfigSetsDir(Path solrInstallDir) {
     Path configSetsPath = Paths.get("server/solr/configsets/");
     return solrInstallDir.resolve(configSetsPath);
   }
+
+  public static boolean isWindows() {
+    return (OS.isFamilyDOS() || OS.isFamilyWin9x() || OS.isFamilyWindows());
+  }
 }
diff --git a/solr/core/src/java/org/apache/solr/cli/RunExampleTool.java b/solr/core/src/java/org/apache/solr/cli/RunExampleTool.java
index c5afdf063212..974039cb66ff 100644
--- a/solr/core/src/java/org/apache/solr/cli/RunExampleTool.java
+++ b/solr/core/src/java/org/apache/solr/cli/RunExampleTool.java
@@ -42,7 +42,6 @@
 import org.apache.commons.exec.DefaultExecutor;
 import org.apache.commons.exec.ExecuteException;
 import org.apache.commons.exec.Executor;
-import org.apache.commons.exec.OS;
 import org.apache.commons.exec.environment.EnvironmentUtils;
 import org.apache.commons.io.file.PathUtils;
 import org.apache.solr.client.solrj.SolrClient;
@@ -695,7 +694,7 @@ protected Map<String, Object> startSolr(
     Path cwd = Path.of(System.getProperty("user.dir"));
     Path binDir = Path.of(script).getParent();
 
-    boolean isWindows = (OS.isFamilyDOS() || OS.isFamilyWin9x() || OS.isFamilyWindows());
+    boolean isWindows = CLIUtils.isWindows();
     String callScript = (!isWindows && cwd.equals(binDir.getParent())) ? "bin/solr" : script;
 
     String cwdPath = cwd.toAbsolutePath().toString();
diff --git a/solr/core/src/test/org/apache/solr/cli/CLIUtilsTest.java b/solr/core/src/test/org/apache/solr/cli/CLIUtilsTest.java
index 928266de7c00..d1806aec6703 100644
--- a/solr/core/src/test/org/apache/solr/cli/CLIUtilsTest.java
+++ b/solr/core/src/test/org/apache/solr/cli/CLIUtilsTest.java
@@ -28,7 +28,7 @@ public class CLIUtilsTest extends SolrCloudTestCase {
   @Test
   public void testDefaultSolrUrlWithNoProperties() {
     System.clearProperty("solr.url.scheme");
-    System.clearProperty("solr.tool.host");
+    System.clearProperty("solr.host");
     System.clearProperty("jetty.port");
     assertEquals(
         "Default Solr URL should match with no properties set.",
@@ -39,7 +39,7 @@ public void testDefaultSolrUrlWithNoProperties() {
   @Test
   public void testDefaultSolrUrlWithProperties() {
     System.setProperty("solr.url.scheme", "https");
-    System.setProperty("solr.tool.host", "other.local");
+    System.setProperty("solr.host", "other.local");
     System.setProperty("jetty.port", "1234");
     assertEquals(
         "Default Solr URL should match with custom properties set.",
diff --git a/solr/packaging/test/test_auth.bats b/solr/packaging/test/test_auth.bats
index eff96d9d81b6..58a0ad16ee58 100644
--- a/solr/packaging/test/test_auth.bats
+++ b/solr/packaging/test/test_auth.bats
@@ -48,3 +48,37 @@ setup() {
   assert_output --partial '"numFound":0'
   solr stop --all
 }
+
+@test "enable auth connects via zookeeper" {
+  solr start
+  run solr auth enable --type basicAuth --credentials name:password -z localhost:${ZK_PORT}
+  assert_output --partial 'Successfully enabled basic auth'
+  run curl -u name:password --basic "http://localhost:${SOLR_PORT}/api/cluster"
+  assert_output --partial '"status":0'
+  
+  solr auth disable -z localhost:${ZK_PORT}
+  run curl "http://localhost:${SOLR_PORT}/api/cluster"
+  assert_output --partial '"status":0' 
+  solr stop --all
+}
+
+@test "AUTH_PORT delegates to SOLR_PORT" {
+  solr start -p ${SOLR2_PORT}
+  
+  export AUTH_PORT=${SOLR2_PORT}
+  
+  unset SOLR2_PORT
+  assert [ -z "${SOLR2_PORT}" ]
+  
+  solr auth enable --type basicAuth --credentials name:password
+  solr assert --started http://localhost:${AUTH_PORT} --timeout 5000
+
+  run curl -u name:password --basic "http://localhost:${AUTH_PORT}/api/cluster"
+  assert_output --partial '"status":0'
+  
+  solr auth disable
+  run curl "http://localhost:${AUTH_PORT}/api/cluster"
+  assert_output --partial '"status":0' 
+  solr stop --all
+  export SOLR2_PORT=${AUTH_PORT}
+}