whitelisting IP addresses for functioning of mirror site - .htaccess

Question

I really need help regarding my website's mirror site functioning..my website is elementlimousine.com and the mirror site url is elementslimousine.net
I am not much of a techie so excuse my ignorance and simplicity of language.
I have a website for which I am getting search engine marketing done through third party. They way they do it is make a mirror site (with a different url), which will take information from original site and display it to the user.
But the problem we are facing is on clicking the mirror site url, a 500 error shows up. The team said it is happening because the mirror site is talking very frequently to the original site. So the only solution according to them is white list their IP addresses:
74.122.36.157
204.14.212.132
74.122.37.11
74.122.36.0 – 74.122.36.255 (256 IPs)
74.122.37.0 – 74.122.37.255 (256 IPs)
But it is still not working and the campaign has been paused..so now elementslimousine.net does work
Did I put the code wrong or at wrong place in htaccess file?
Is there anything else that can be done to make mirroring work?
I will really appreciate any help in this!
Thanks
According to other posts, I opened my .htacces file and changed code to this:
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
order allow, deny
allow from 74.122.36.157
allow from 204.14.212.132
allow from 74.122.37.11
allow from 74.122.36.0 – 74.122.36.255
allow from 74.122.37.0 – 74.122.37.255
# BEGIN wtwp_cache
<IfModule mod_mime.c>
# Text
AddType text/css .css
AddType application/x-javascript .js
AddType text/html .html .htm
AddType text/richtext .rtf .rtx
AddType text/plain .txt
AddType text/xml .xml
# Image
AddType image/gif .gif
AddType image/x-icon .ico
AddType image/jpeg .jpg .jpeg .jpe
AddType image/png .png
AddType image/svg+xml .svg .svgz
# Video
AddType video/asf .asf .asx .wax .wmv .wmx
AddType video/avi .avi
AddType video/quicktime .mov .qt
AddType video/mp4 .mp4 .m4v
AddType video/mpeg .mpeg .mpg .mpe
# PDF
AddType application/pdf .pdf
# Flash
AddType application/x-shockwave-flash .swf
# Font
AddType application/x-font-ttf .ttf .ttc
AddType application/vnd.ms-fontobject .eot
AddType application/x-font-otf .otf
# Audio
AddType audio/mpeg .mp3 .m4a
AddType audio/ogg .ogg
AddType audio/wav .wav
AddType audio/wma .wma
# Zip/Tar
AddType application/x-tar .tar
AddType application/x-gzip .gz .gzip
AddType application/zip .zip
</IfModule>
<IfModule mod_expires.c>
ExpiresActive On
# Text
ExpiresByType text/css A31536000
ExpiresByType application/x-javascript A31536000
ExpiresByType text/html A3600
ExpiresByType text/richtext A3600
ExpiresByType text/plain A3600
ExpiresByType text/xml A3600
# Image
ExpiresByType image/gif A31536000
ExpiresByType image/x-icon A31536000
ExpiresByType image/jpeg A31536000
ExpiresByType image/png A31536000
ExpiresByType image/svg+xml A31536000
# Video
ExpiresByType video/asf A31536000
ExpiresByType video/avi A31536000
ExpiresByType video/quicktime A31536000
ExpiresByType video/mp4 A31536000
ExpiresByType video/mpeg A31536000
# PDF
ExpiresByType application/pdf A31536000
# Flash
ExpiresByType application/x-shockwave-flash A31536000
# Font
ExpiresByType application/x-font-ttf A31536000
ExpiresByType application/vnd.ms-fontobject A31536000
ExpiresByType application/x-font-otf A31536000
# Audio
ExpiresByType audio/mpeg A31536000
ExpiresByType audio/ogg A31536000
ExpiresByType audio/wav A31536000
ExpiresByType audio/wma A31536000
# Zip/Tar
ExpiresByType application/x-tar A31536000
ExpiresByType application/x-gzip A31536000
ExpiresByType application/zip A31536000
</IfModule>
<FilesMatch "\.(?i:css|js|htm|html|rtf|rtx|txt|xml|gif|ico|jpg|jpeg|jpe|png|svg|svgz|asf|asx|wax|wmv|wmx|avi|mov|qt|mp4|m4v|mpeg|mpg|mpe|pdf|swf|ttf|ttc|eot|otf|mp3|m4a|ogg|wav|wma|tar|gz|gzip|zip)$">
<IfModule mod_headers.c>
Header set Pragma "public"
Header append Cache-Control "public, must-revalidate, proxy-revalidate"
Header unset ETag
</IfModule>
</FilesMatch>
<FilesMatch "\.(?i:css|js|gif|ico|jpg|jpeg|jpe|png|pdf|swf|ttf|ttc|eot|otf)$">
<IfModule mod_headers.c>
Header unset Set-Cookie
</IfModule>
</FilesMatch>
# END wtwp_cache
# BEGIN wtwp_security
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^wp-admin/includes/ - [F,L]
RewriteRule !^wp-includes/ - [S=3]
RewriteRule ^wp-includes/[^/]+\.php$ - [F,L]
RewriteRule ^wp-includes/js/tinymce/langs/.+\.php - [F,L]
RewriteRule ^wp-includes/theme-compat/ - [F,L]
</IfModule>
<Files "wp-config.php">
Order allow,deny
Deny from all
</Files>
Options -Indexes
# END wtwp_security

Answer 1

There is some syntax error.
Try this block and replace your relevant code:
order deny,allow
deny from All
allow from 74.122.36.157
allow from 204.14.212.132
allow from 74.122.37.11
allow from 74.122.36.0 74.122.36.255
allow from 74.122.37.0 74.122.37.255
MOre details about it: http://httpd.apache.org/docs/current/mod/mod_access_compat.html