# Nginx + apache : REMOTE\_ADDR and REMOTE\_HOST bug **URL:** \ **Category:** NGINX\ **Created:** [August 30, 2011, 6:07pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244 "2011-08-30T18:07:19Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\ **Post date:** [August 30, 2011, 6:07pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/1 "2011-08-30T18:07:19Z")
Hello, i’ve got a “funny” bug. My installation is Nginx 1.0 and apache ( httpd ) behind. Apache got’s mod\_rpaf activated and HostNameLookups On. When testing a php script i find this problem : \_SERVER[“REMOTE\_HOST”]\*\*\*\*\*\*\*\*\*\*\*\*\<= my webserver hostname \_SERVER[“REMOTE\_ADDR”]82.125.151.3\<= my ip Any idea ??? it’s really strange. Thank you ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 6:20pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/2 "2011-08-30T18:20:52Z")
Hello! On Tue, Aug 30, 2011 at 06:06:37PM +0200, Albuquerque R. wrote: > \_SERVER[“REMOTE\_ADDR”]82.125.151.3\<= my ip > I.e. client’s ip is correct, but client’s hostname still points to > your webserver, right? This looks like problem in mod\_rpaf. Maxim D. ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 6:23pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/3 "2011-08-30T18:23:57Z")
Yes that’s right. It’s really strange that i’m the only one having this problem with mod\_rpaf 0.6 ☹ ☹ ☹ 2011/8/30 Maxim D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 6:35pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/4 "2011-08-30T18:35:41Z")
BTW it’s not good idea to use HostNameLookups on production site since these lookups may take long enough time. – Igor S. 30.08.2011, 20:23, Albuquerque R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) (): ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 6:44pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/5 "2011-08-30T18:44:21Z")
Tha’s right but i really need this info… ☹ 2011/8/30 Igor S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 6:48pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/6 "2011-08-30T18:48:04Z")
proxy\_set\_header Host $host; proxy\_set\_header X-Real-IP $remote\_addr; proxy\_set\_header X-Forwarded-For $proxy\_add\_x\_forwarded\_for; And on apache : LoadModule rpaf\_module modules/mod\_rpaf-2.0.so RPAFenable On RPAFsethostname On RPAFproxy\_ips 127.0.0.1 RPAFheader X-Forwarded-For 2011/8/30 Jim O. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 6:44pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/7 "2011-08-30T18:44:20Z")
On 8/30/11 12:23 PM, Albuquerque R. wrote: > ``` > > Hello, > > I.e. client's ip is correct, but client's hostname still points to > your webserver, right? This looks like problem in mod_rpaf. > > ``` It looks like it’s reporting _his_ IP, not that of the client and Apache is doing a look up on that IP? How are you passing the remote IP from nginx to Apache? > * * * > > nginx mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [mailman.nginx.org archive](http://mailman.nginx.org/mailman/listinfo/nginx) – Jim O. ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 7:38pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/8 "2011-08-30T19:38:41Z")
On 8/30/11 12:47 PM, Albuquerque R. wrote: > RPAFenable On > RPAFsethostname On > RPAFproxy\_ips 127.0.0.1 > RPAFheader X-Forwarded-For Please do not top post. It makes following a thread much more difficult. We use the following in Apache: RPAFenable On RPAFsethostname On RPAFproxy\_ips 127.0.0.1 First thing I would suggest is running a phpinfo script and seeing what the value of \_SERVER[“REMOTE\_ADDR”] is. Then comment out the line that begins with “RPAF header”, restart Apache and run again and see if the value changes. > ``` > this > > > > > _SERVER["REMOTE_ADDR"]82.125.151.3<= my ip > > > > > nginx mailing list > removed_email_address@domain.invalid > http://mailman.nginx.org/mailman/listinfo/nginx > > ``` > > * * * > > nginx mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [mailman.nginx.org archive](http://mailman.nginx.org/mailman/listinfo/nginx) – Jim O. ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 8:30pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/9 "2011-08-30T20:30:34Z")
2011/8/30 Jim O. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > LoadModule rpaf\_module modules/mod\_rpaf-2.0.so [http://mod\_rpaf-2.0.so](http://mod_rpaf-2.0.so) > > RPAFenable On > > RPAFsethostname On > > RPAFproxy\_ips 127.0.0.1 > > First thing I would suggest is running a phpinfo script and seeing what > the value of \_SERVER[“REMOTE\_ADDR”] is. > > Changes done, nothing changed.. Still the same problem…The fact is that > > it seems mod\_rpaf is working well because REMOTE\_ADDR is good, but > > REMOTE\_HOST is not good ☹ ☹ ☹ ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 10:18pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/10 "2011-08-30T22:18:42Z")
On 8/30/11 2:29 PM, Albuquerque R. wrote: > ``` > > > > ``` > > > > Changes done, nothing changed.. Still the same problem…The fact is > > > that it seems mod\_rpaf is working well because REMOTE\_ADDR is good, but > > > REMOTE\_HOST is not good ☹ ☹ ☹ I agree. It is not resolving the IP incorrectly. It is not an issue with nginx or with mod\_rpaf. > ``` > > > > > > Rui wrote: > > > > _SERVER["REMOTE_HOST"] ************ <= my webserver hostname > > How are you passing the remote IP from nginx to Apache? > >> > > > > > > ``` > > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [mailman.nginx.org archive](http://mailman.nginx.org/mailman/listinfo/nginx) – Jim O. ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 31, 2011, 1:15am UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/11 "2011-08-31T01:15:52Z")
On 8/30/11 5:50 PM, Maxim D. wrote: > > > REMOTE\_HOST is not good ☹ ☹ ☹ > > > … this is obviously a problem in mod\_rpaf. It fails to change > > > ip _before_ resolving happens in Apache. (No idea if it’s actually > > > possible to implement this correctly though.) Maxim, we could argue this pedantically all night long and never agree. However, mod\_rpaf is doing exactly what it’s designed to do which is to report the remote IP address correctly. HostNameLookups is _not_ a function of mod\_rpaf, it is a function of Apache core. However… the function works properly in _my_ testing as follows. I created a small php script as follows: \ I turned on “HostNameLookups” in Apache. Attached is the result. This is indeed my IP and host. Why it’s not working for the OP I cannot explain, but it does seem to work _correctly_ as does “HostNameLookups” directive. ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 31, 2011, 8:35am UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/12 "2011-08-31T08:35:57Z")
2011/8/31 Jim O. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > > > that it seems mod\_rpaf is working well because REMOTE\_ADDR is good, but > > > > \> \> your webserver, right? This looks like problem in > > ?\> > > > While accessing the page directly from apache i’ve got the good values > > too. But when i pass by nginx then apache ( mod\_rpaf ) the hostname is > > not > > right ☹ ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 30, 2011, 11:50pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/13 "2011-08-30T23:50:38Z")
Hello! On Tue, Aug 30, 2011 at 04:17:52PM -0400, Jim O. wrote: > On 8/30/11 2:29 PM, Albuquerque R. wrote: […] > > > > Changes done, nothing changed.. Still the same problem…The fact is > > > > that it seems mod\_rpaf is working well because REMOTE\_ADDR is good, but > > > > REMOTE\_HOST is not good ☹ ☹ ☹ > > I agree. It is not resolving the IP incorrectly. It is not an issue with > nginx or with mod\_rpaf. As I wrote in my original reply… > > ``` > > > > I.e. client's ip is correct, but client's hostname still > > > > ``` points to > > ``` > > > > your webserver, right? This looks like problem in mod_rpaf. > > > > ``` … this is obviously a problem in mod\_rpaf. It fails to change ip _before_ resolving happens in Apache. (No idea if it’s actually possible to implement this correctly though.) Maxim D. ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 31, 2011, 9:03am UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/14 "2011-08-31T09:03:46Z")
2011/8/31 Albuquerque R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > > > nginx or with mod\_rpaf. > > > > possible to implement this correctly though.) > > > > \ ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 31, 2011, 12:59pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/15 "2011-08-31T12:59:55Z")
On 31.08.2011 10:03, Albuquerque R. wrote: > While accessing the page directly from apache i’ve got the good > values too. But when i pass by nginx then apache ( mod\_rpaf ) the > hostname is not right ☹ in request from nginx to apache backend - you set correct client hostname in the X-Forwarded-Host or X-Host header? RPAFsethostname on; means what you must provide desirable client hostname: ## source of mod\_rpaf-0.6\mod\_rpaf-2.0.c if (cfg-\>sethostname) { const char _hostvalue; if (hostvalue = apr\_table\_get(r-\>headers\_in, “X-Forwarded-Host”)) { /_ 2.0 proxy frontend or 1.3 =\> 1.3.25 proxy frontend _/ apr\_table\_set(r-\>headers\_in, “Host”, apr\_pstrdup(r-\>pool, hostvalue)); r-\>hostname = apr\_pstrdup(r-\>pool, hostvalue); ap\_update\_vhost\_from\_headers(r); } else if (hostvalue = apr\_table\_get(r-\>headers\_in, “X-Host”)) { /_ 1.3 proxy frontend with mod\_proxy\_add\_forward \*/ apr\_table\_set(r-\>headers\_in, “Host”, apr\_pstrdup(r-\>pool, hostvalue)); r-\>hostname = apr\_pstrdup(r-\>pool, hostvalue); ap\_update\_vhost\_from\_headers(r); } } – Best regards, Gena ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 31, 2011, 1:58pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/16 "2011-08-31T13:58:35Z")
2011/8/31 Gena M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > RPAFsethostname on; > apr\_table\_set(r-\>headers\_in, “Host”, apr\_pstrdup(r-\>pool, > } In fact event with RPAFsethostname on; commented, there’s a problem. In this case we are talking about client remote hostname… ---
**Author:** ![Albuquerque\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f19dbf/32.png) [@Albuquerque\_R](https://www.ruby-forum.com/u/Albuquerque_R)\ **Post date:** [August 31, 2011, 2:46pm UTC](https://www.ruby-forum.com/t/nginx-apache-remote-addr-and-remote-host-bug/211244/17 "2011-08-31T14:46:09Z")
On 31.08.2011 14:57, Albuquerque R. wrote: > While accessing the page directly from apache i’ve got the good > values too. But when i pass by nginx then apache ( mod\_rpaf ) the > hostname is not right ☹ […] > In this case we are talking about client remote hostname… probably this is bug / misfeature in mod\_rpaf / apache+mod\_rpaf. and obviously such behavior of apache+mod\_rpaf is not nginx bug. mod\_rpaf change only client IP and not change client hostname see details in fuction “change\_remote\_ip” in mod\_rpaf sources p.s. most probably this is mod\_rpaf bug / misfeature. may be try ask support in mod\_rpaf/apache mail lists? – Best regards, Gena