[DOCS] Merges duplicate pages for Kerberos realms (elastic#49207)

Author: lcawl

docs/reference/redirects.asciidoc

@@ -969,3 +969,9 @@ See <<ref-ldap-settings>>.
 === Setting up SSL between Elasticsearch and LDAP
 
 See <<tls-ldap>>. 
+
+[role="exclude",id="configuring-kerberos-realm"]
+=== Configuring a Kerberos realm
+
+See <<kerberos-realm-configuration>>.
+

x-pack/docs/en/security/authentication/configuring-kerberos-realm.asciidoc

@@ -1,7 +1,3 @@
-[role="xpack"]
-[[configuring-kerberos-realm]]
-=== Configuring a Kerberos realm
-
 Kerberos is used to protect services and uses a ticket-based authentication
 protocol to authenticate users.
 You can configure {es} to use the Kerberos V5 authentication protocol, which is 
@@ -15,9 +11,8 @@ Refer to your Kerberos installation documentation for more information about
 obtaining TGT. {es} clients must first obtain a TGT then initiate the process of 
 authenticating with {es}.
 
-For a summary of Kerberos terminology, see <<kerberos-realm>>.
-
-==== Before you begin
+[[kerberos-realm-prereq]]
+===== Before you begin
 
 . Deploy Kerberos. 
 +
@@ -51,7 +46,8 @@ For more information on Java GSS, see
 https://docs.oracle.com/javase/10/security/kerberos-requirements1.htm[Java GSS Kerberos requirements]
 --
 
-==== Create a Kerberos realm
+[[kerberos-realm-create]]
+===== Create a Kerberos realm
 
 To configure a Kerberos realm in {es}:
 
@@ -176,4 +172,3 @@ NOTE: The Kerberos realm supports
 alternative to role mapping.
 
 --
-

x-pack/docs/en/security/authentication/kerberos-realm.asciidoc

@@ -7,11 +7,9 @@ authentication, an industry standard protocol to authenticate users in {es}.
 
 NOTE: You cannot use the Kerberos realm to authenticate on the transport network layer.
 
-To authenticate users with Kerberos, you need to
-{ref}/configuring-kerberos-realm.html[configure a Kerberos realm] and
-<<mapping-roles, map users to roles>>.
-For more information on realm settings, see
-{ref}/security-settings.html#ref-kerberos-settings[Kerberos realm settings].
+To authenticate users with Kerberos, you need to configure a Kerberos realm and
+map users to roles. For more information on realm settings, see
+<<ref-kerberos-settings>>.
 
 [[kerberos-terms]]
 ==== Key concepts
@@ -59,4 +57,9 @@ realm session key encryption types.
 
 _ticket granting ticket (TGT)_::
 A TGT is an authentication ticket generated by the Kerberos authentication
-server. It contains an encrypted authenticator.
+server. It contains an encrypted authenticator.
+
+[[kerberos-realm-configuration]]
+==== Configuring a Kerberos realm
+
+include::configuring-kerberos-realm.asciidoc[]

x-pack/docs/en/security/configuring-es.asciidoc

@@ -74,7 +74,7 @@ your subscription. For more information, see https://www.elastic.co/subscription
 --
 ** <<configuring-ad-realm,Active Directory realms>>
 ** <<file-realm,File realms>>
-** <<configuring-kerberos-realm,Kerberos realms>>
+** <<kerberos-realm,Kerberos realms>>
 ** <<ldap-realm,LDAP realms>>
 ** <<native-realm,Native realms>>
 ** <<configuring-pki-realm,PKI realms>>
@@ -147,7 +147,6 @@ include::securing-communications/separating-node-client-traffic.asciidoc[]
 
 include::authentication/configuring-active-directory-realm.asciidoc[]
 include::authentication/configuring-pki-realm.asciidoc[]
-include::authentication/configuring-kerberos-realm.asciidoc[]
 
 include::reference/files.asciidoc[]
 include::fips-140-compliance.asciidoc[]