Negation of Remote_Addr in SetEnvIf directive

[Krzysztof Dajka <alteriks@xxxxxxxxx>]

Hi,

I have a bunch of apache servers which are load balanced. I have configured them in such manner that each server adds header

X-Server-Name with proper hostname. 

In my apache.conf I have:

PassEnv HOSTNAME
Header add X-Server-Name "%{HOSTNAME}e"

I have exported HOSTNAME before launching apache and everything works as it should.

But I would like to configure apache to show hostname only for my inner network 10.

So I added SetEnvIf:

PassEnv HOSTNAME
SetEnvIf Remote_Addr !^10\. HOSTNAME=foo.bar.com
Header add X-Server-Name "%{HOSTNAME}e"

but negation of network didn't work, I have also tried:

SetEnvIf Remote_Addr [^(10\.)] HOSTNAME=foo.bar.com

but it didn't worked either. 

Has anyone used negation in SetEnvIf Remote_Addr ?

Documentation says:

Syntax:    SetEnvIf attribute regex [!]env-variable[=value] [[!]env-variable[=value]] ...

so why any of those regex's doesn't work?

Thanks in advance