LTM : Troubleshooting with no source IP

Hi imabbas_90, you can create a data-group to contain your gcp ip ranges, I was able to do that programmatically against that json data with a little python (where gcp_src.json is a file with what you linked above.)

import json

with open('gcp_src.json') as f:
   data = json.load(f)

f1 = open('gcp_src_dg', 'w')

f1.write('ltm data-group internal gcp_sources {\n')
f1.write('    records {\n')
for prefix in data.get('prefixes'):
    if 'ipv4Prefix' in prefix:
        f1.write(f'        {prefix.get("ipv4Prefix")} {{ }}\n')
    elif 'ipv6Prefix' in prefix:
        f1.write(f'        {prefix.get("ipv6Prefix")} {{ }}\n')
f1.write('    }\n')
f1.write('    type ip\n')
f1.write('}\n')

f1.close()

Then in an iRule, you can just log against sources that match that range in the data-group:

when HTTP_REQUEST {
    if {[class match [IP::client_addr] equals gcp_sources]} {
        log local0. "Client IP: [IP::client_addr] matches GCP source..."
    }
}

I'd recommend you take a heavily filtered packet capture as well by actively triggering the job when capturing.