この度、Railsで作成したアプリを、Capistrano3.4でEC2にデプロイしたいのですが、下記コマンドを実行後、エラーが発生してしまいデプロイができません。

環境

EC2
Rails4
Unicorn
Nginx
Capistrano3

実行したコマンド

[ec2-user@ip-172-31-30-10 ec2_test_app]$ pwd
/var/www/ec2_test_app/ec2_test_app

[ec2-user@ip-172-31-30-10 ec2_test_app]$ bundle exec cap production deploy

エラー文

(Backtrace restricted to imported tasks)
cap aborted!
Net::SSH::AuthenticationFailed: Authentication failed for user ec2-user@32.826.472.663
Tasks: TOP => rbenv:validate
(See full trace by running task with --trace)

デプロイで参考にしたサイト

http://qiita.com/SanoHiroshi/items/d7942d66678f0d60f0ed

設定ファイル等

nginx.conf

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /var/run/nginx.pid;
events {
    worker_connections 2048;
}

http {
    root  /var/www/ec2_test_app/current;
    upstream unicorn-server {
        server unix:/var/www/ec2_test_app/shared/tmp/sockets/unicorn.sock
        fail_timeout=0;
     }
   server {
      listen 80;
      client_max_body_size 4G;
      server_name 32.826.472.663;
      keepalive_timeout 80;
     access_log /var/log/nginx/access.log;
     error_log /var/log/nginx/error.log;
     root  /var/www/ec2_test_app/current;
     location ~ ^/assets/ {
        include /etc/nginx/mime.types;
        root    /var/www/ec2_test_app/current/public;
     }
     location / {
           proxy_pass http://unicorn-server;
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
           proxy_set_header Host $host;
     }
     error_page   500 502 503 504  /500.html;
     location = /500.html {
         root /var/www/ec2_test_app/current/public;
     }
  }
}

Gemfile

group :production, :staging do
 gem 'unicorn'
end

group :development do
gem 'capistrano', '~> 3.4'
gem 'capistrano-rails',   '~> 1.1', require: false
gem 'capistrano-bundler', '~> 1.1', require: false
gem 'capistrano-rbenv', '~> 2.0', require: false
gem 'capistrano3-unicorn'
end

Capfile

require 'capistrano/setup'
require 'capistrano/deploy'
require 'capistrano/rails'
require 'capistrano/rbenv'
Dir.glob("lib/capistrano/tasks/*.rake").each { |r| import r }

config/deploy.rb

set :application, 'ec2_test_app'
set :repo_url, 'git@github.com:hoge-fuga/ec2_test_app.git'
set :branch, 'master'

set :deploy_to, '/var/www/ec2_test_app/ec2_test_app'
set :keep_releases, 5
set :rbenv_type, :user
set :rbenv_ruby, '2.3.0'
set :rbenv_map_bins, %w{rake gem bundle ruby rails}
set :rbenv_roles, :all
set :linked_dirs, %w{bin log tmp/backup tmp/pids tmp/cache tmp/sockets vendor/bundle}
after 'deploy:publishing', 'deploy:restart'
namespace :deploy do
  task :restart do
   invoke 'unicorn:restart'
  end
end

config/unicorn.rb

application = 'reserve-hacker'
worker_processes 2
app_path = "/var/www/ec2_test_app/ec2_test_app"
listen "#{app_path}/shared/tmp/sockets/unicorn.sock"
pid "#{app_path}/current/tmp/unicorn.pid"
timeout 60
preload_app true
stdout_path "#{app_path}/current/log/production.log"
stderr_path "#{app_path}/current/log/production.log"
GC.respond_to?(:copy_on_write_friendly=) and GC.copy_on_write_friendly = true

config/deploy/production.rb

set :stage, :production
set :rails_env, 'production'
server '32.826.472.663', user: 'ec2-user',
roles: %w{web app db}
set :ssh_options, {
 keys: [File.expand_path('~/.ssh/id_rsa.pem)')]
}

エラーが発生して、デプロイできない原因をアドバイス頂きたいです。

また、今まで見れていたNginxの画面が、下記URLを叩いても404 Not Foundが表示されて、急に見れなくなってしまいました。
http://192.0.2.100 (数字は適当)
こちらも原因をアドバイス頂きたいです。

何卒宜しくお願い致します。