Help with SetEnvIf?

Question

Apache HTTP Server

I can’t find something in the Apache docs, how to make such a feature: set an environment variable if Remote_Addr and Server_Addr match .
The syntax is:

SetEnvIf <env_var> <regexp> <value1=1> <valuen=n>

Trying:
SetEnvIf Remote_Addr Server_Addr IN_DEV=1
Doesn't work. Apparently, you need to correctly substitute <regexp>. Can anyone suggest how to solve my issue?

Answer 1

RewriteEngine on
RewriteCond %{SERVER_ADDR}_%{REMOTE_HOST} ^([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)_\1$
RewriteRule .*          -       [E=IN_DEV:1]