anchor.diff:  create an NS record in the DNS server for *mydomain.com*
   for each address in the delegation set.
   
  -#### <a id='deployment-env-prep'></a> Prepare the Deployment Environment ####
  -
  -Ruby 1.9.3 and git (1.8 or later) are prerequisites for the following
  -steps. After you install Ruby and git, install the `bundler` RubyGem:
  -
  -<pre class="terminal">
  -$ gem install bundler
  -</pre>
  -
  -Create a directory for your planned deployment.
  -In that directory:
  -
  -1. Create a file named `Gemfile` with the following contents:
  -
  -~~~
  -source 'https://rubygems.org'
  -
  -ruby "1.9.3"
  -
  -gem "bosh_cli_plugin_aws"
  -~~~
  -
  -1. Run the `bundle install` command.
  -
  +#### <a id='domain-prep'></a> Prepare a Domain ####
   
   Next, set environment variables required for deploying to AWS. Create
   a file called `bosh_environment` and add the following, changing the
  
positive.code: 
  ### <a id='aws'></a> AWS ###
  
  #### <a id='domain-prep'></a> Prepare a Domain ####
  
  First, pick a DNS domain name for the environment you plan to deploy.
  If you pick *cloud.mydomain.com*, your applications will be available as
  *app-name.cloud.mydomain.com*.
  
  Create an AWS Route 53 Hosted Zone for your domain at the
  
negative.code: `BOSH_VPC_DOMAIN` and `BOSH_VPC_SUBDOMAIN` must correspond to the
  DNS domain name you set up when configuring Route 53.
  
  The only supported value for `BOSH_AWS_REGION` is `us-east-1`.
  
  Choose availability zones that are listed as "operating normally" on
  the [AWS Console Status Health Section](https://console.aws.amazon.com/ec2/v2/home?region=us-east-1)
  