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##### SUMMARY
elb_network_lb and elb_target_group should support UDP, currently only HTTP, HTTPS and TCP are supported by ansible.

Based on the current pages, UDP and TCP_UDP are supported as protocols:
- https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-listener.html
- https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-target-group.html

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
- elb_target_group
- elb_network_lb

##### ADDITIONAL INFORMATION
It would be useful to use UDP as a protocol for an NLB, additionally, attached target groups would need to support UDP.

TCP_UDP is another protocol that it would be useful to add support for (a port that would take TCP or UDP traffic and not care)

<!--- Paste example playbooks or commands between quotes below -->
```yaml
    - name: Create logstash target group
      elb_target_group:
        name: logstash_bunyan_production_tg
        protocol: udp
        port: 5600
        vpc_id: "{{ vpc_facts.vpcs[0].id }}"
        state: present

    - name: Create nlb
      elb_network_lb:
        name: logstash_nlb
        subnets: "{{ private_subnets + public_subnets }}"
        health_check_path: "/"
        health_check_port: "9600"
        health_check_protocol: "http"
        protocol: "udp"
        port: "5600"
        listeners:
          - Protocol: UDP
            Port: 5600
            DefaultActions:
              - Type: forward
                TargetGroupName: logstash_bunyan_production_tg
        state: present
```

<!--- HINT: You can also paste gist.github.com links for larger files -->

- The port on which the targets receive traffic. This port is used unless you specify a port override when registering the target. Required if
        I(state) is C(present).
    required: false
    type: int
  protocol:
    description:
      - The protocol to use for routing traffic to the targets. Required when I(state) is C(present).
    required: false
    choices: [ 'http', 'https', 'tcp', 'HTTP', 'HTTPS', 'TCP']
    type: str
  purge_tags:
    description:
      - If yes, existing tags will be purged from the resource to match exactly what is defined by I(tags) parameter. If the tag parameter is not set then
        tags will not be modified.
    required: false
    default: yes
    type: bool
  state:
    description:
      - Create or destroy the target group.
    required: true
    choices: [ 'present', 'absent' ]
    type: str
  stickiness_enabled:
    description:
      - Indicates whether sticky sessions are enabled.
    type: bool
  stickiness_lb_cookie_duration:
    description:
      - The time period, in seconds, during which requests from a client should be routed to the same target. After this time period expires, the load