proxy_bind with hostname from /etc/hosts possible?

larsg nginx-forum at
Mon Mar 13 14:38:12 UTC 2017


is it possible to use an hostname from local /etc/hosts as proxy_bind
In our current

We use nginx 1.8.1 as reverse proxy.
In order to overcome the "Overcoming Ephemeral Port Exhaustion" problem
(64k+ connections), we use proxy_bind to iterate over all loccally available
IP addresses and assign them as source IP (see
In order to have an generic nginx configuration for all of our nginx
instances, we don't want to hard code server specific IPs in the nginx.conf
but use hostnames that are defined in the local /etc/hosts.

You can see our current configuration above.
Unfortunately nginx cannot resolve the hostname (localip0 etc.). There is an
error log "invalid local address "localip0"...).
We also tested the usage of upstream directive. Same result.
I'm worry that I only can use explicit IP addresses in this situation. Or do
you have an alternative solution?

/etc/host: localip0 localip1


split_clients "${remote_addr}${remote_port}AAAA" $source_ip {
  10% localip0;
  10% localip1;

server {
  listen              443;
  proxy_bind          $source_ip;

Posted at Nginx Forum:,272918,272918#msg-272918

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