Preserve client ip through load-balancer firewall

[Nuthan Kumar]

Hi,

We could configure http load-balancer firewall for an instance group. We have a scenario where, we need client ip(request ip) to be preserved till the application(instance), as we are serving location based content for different countries based on ip.

In the web server access logs, the client ip is always of the range 130.211.0.0/22. Learnt. thats load-balancer IP. Is there any other rule that I need to add to forward the IPs from the firewall.

Please help.

Thanks,

Nuthan.

[Carlos (Cloud Platform Support)]

Hi Nuthan,

The Google network load balancer does not proxy the connections and the client IP is not changed.

The behavior of the HTTP load balancer is quite different since it proxies the connections. You can always retrieve the original client IP from the X-Forwarded-For HTTP header parse by the the Target proxy. As explained in the same article you must allow traffic from 130.211.0.0/22 and 35.191.0.0/16 subnets for the HC and the traffic coming from the LB to reach your backends.

[Nuthan Kumar]

Thanks Carlos, Client IP retrieved from X-Forwarded-For HTTP header.