How to block all requests that do not belong to a defined route in Spring Cloud Gateway

Question

I have this yml where I define the routes for Spring Cloud Gateway

spring:
  cloud:
    gateway:
      routes:
        - id: auth_external_rewrite_path
          uri: lb://<service-1>
          predicates:
            - Path=/mypath1
          filters:
            - RewritePath=/mypath1, /myrewritepath1

        - id: auth_federated_login_rewrite_path
          uri: lb://<service-2>
          predicates:
            - Path=/mypath2
          filters:
            - RewritePath=/mypath2, /mypathrewrite2

As you can see I use the lb uri beacuse services behind these uri are discovered through an Eureka Server dynamically.

The question is: how can I block requests that aren't defined into the yaml ?

For example: a request to http://host/service-1 should pass but a request to http://host/service-not-definied-in-my-yaml should not be forwarded by the gateway