/etc/guacamole/guacamole.properties

lib-directory: /var/lib/tomcat/webapps/guacamole/WEB-INF/classes

# Auth provider class (authenticates user/pass combination, needed if using the provided login screen)
#auth-provider: net.sourceforge.guacamole.net.basic.BasicFileAuthenticationProvider
#basic-user-mapping: /etc/guacamole/user-mapping.xml

# Auth provider class
auth-provider: net.sourceforge.guacamole.net.auth.ldap.LDAPAuthenticationProvider

# LDAP properties
ldap-hostname:           ldap.mngt.bh.helux.nl
ldap-port:               389
ldap-user-base-dn:       ou=people,dc=helux,dc=nl
ldap-username-attribute: cn
ldap-config-base-dn:     ou=guacamole,dc=helux,dc=nl

Allow access from web-server to the Tomcat server

firewall-cmd --permanent --zone=dmz --add-rich-rule="rule family="ipv4" \
source address="46.44.183.184" service name="tomcat" accept"
firewall-cmd --permanent --zone=dmz --add-rich-rule="rule family="ipv6" \
source address="2a02:22a0:bbb7:400::184" service name="tomcat" accept"