docs/ee/ucp/interlock/usage/default-service.md

title	description	keywords
Set a default service	Learn about Interlock, an application routing and load balancing system for Docker Swarm.	ucp, interlock, load balancing

The default proxy service used by UCP to provide layer 7 routing is NGINX, so when users try to access a route that hasn't been configured, they will see the default NGINX 404 page.

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You can customize this by labelling a service with com.docker.lb.default_backend=true. When users try to access a route that's not configured, they are redirected to this service.

As an example, create a docker-compose.yml file with:

version: "3.2"

services:
  demo:
    image: ehazlett/interlock-default-app
    deploy:
      replicas: 1
      labels:
        com.docker.lb.default_backend: "true"
        com.docker.lb.port: 80
    networks:
      - demo-network

networks:
  demo-network:
    driver: overlay

Set up your CLI client with a UCP client bundle, and deploy the service:

docker stack deploy --compose-file docker-compose.yml demo

Once users try to access a route that's not configured, they are directed to this demo service.

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