order allow,deny
SetEnvIF X-Forwarded-For "89.101.211" AllowIP
Allow from env=AllowIP

“88.100.211″ is the pattern meaning “88.100.211*” apache’s mod_setenvif must be enabled “order allow,deny” denies all except “Allow” rules usual “Allow from ip” rules will not work as the load balancer rewrites the “host” header, all requests are coming from the load balancer’s IP the load balancer should set the X-Forwarded-For header

script to check headers:

$headers = getallheaders();