GCP Load Balancer Source IPs for whitelisting

[muthusadhasivam]

Hi,

We have Global HTTP(S) load balancer (classic) with a static IP address and a Cloud function as a backend.

The requirement is to share the IP address with one of the telecom operator to whitelist the source IP to submit the SMS. I've shared the external static IP address of the Load Balancer and Authenticating requests 34.96.0.0/20 and 34.127.192.0/18 to whitelist. The requests time-out even though the IPs has been whitelisted.

Looking at the documentation, "SERVERLESS NEGs and backend buckets: Google's production network handles packet routing"

Is it possible to findout the load balancer's source IP? TIA

[Marvin_Lucero]

Authenticating requests will not help with your endgoal of whitelisting the source IP addresse/s. Authenticating request is intended for external backend, for example NEGs. 

As I understood, your telecom's requirement for whitelisting is the frontend IP address of the load balancer. If you want to obtain the IP address ranges that will be included for whitelisting, this documentation can help you with it. Look for the bullet :

• IP ranges that Google makes available to users on the internet

[muthusadhasivam]

Thanks Marvin for the pointing me to the right documentation.

Let me share the IP ranges with the telecom provider and update the status here.

[muthusadhasivam]

Hi Marvin,

The telecom operator network team had rejected the request stating they can't whitelist all these IP ranges.

Is there a way to fetch the source IPs for asia-south1 region only ?