Bind failed

Server NGINX
1

Hi,

I was doing some tests today and have created a single test virtual host
with
listen 8181;
and nginx runs fine (1.9.7). Now if I change the listen to only one
interface ip:
listen 192.168.10.10:8181
configtest shows fine but reload gives “bind failed” in the error log.
Is this normal?

Thanks!
Frank

2

Hello!

On Tue, Dec 01, 2015 at 12:49:50AM -0800, Frank L. wrote:

Hi,

I was doing some tests today and have created a single test virtual host
with
listen 8181;
and nginx runs fine (1.9.7). Now if I change the listen to only one
interface ip:
listen 192.168.10.10:8181
configtest shows fine but reload gives “bind failed” in the error log.
Is this normal?

Short answer:

Yes, if you are using Linux.

Long answer:

Linux doesn’t allow listen sockets on INADDR_ANY and an IP address
on the same port to coexist, due to “security” reasons. And this
is exactly what happens when you try to reload a configuration -
nginx still has an open listening sockets on *:8181 and tries to
open another one on 192.168.10.10:8181. As a result, the bind()
system call fails due to the Linux limitation, and that’s what you
see in the error log. To switch from a listening on * to an IP
address on Linux you’ll have to restart nginx, reload won’t work.

The same process works fine on other OSes without such artificial
limitations (e.g., FreeBSD).

–
Maxim D.
http://nginx.org/