When you need the literal IP addresses for GCP, use one of the common DNS lookup commands, for example nslookup, dig or host, to retrieve the TXT records for the domain _cloud-netblocks.googleusercontent.com (Figure 1):
$ nslookup -q=TXT _cloud-netblocks.googleusercontent.com 8.8.8.8
Figure 1 Command
This returns a list of the domains included in Google's SPF Record (Figure 2):
_cloud-netblocks1.googleusercontent.com, _cloud-netblocks2.googleusercontent.com,
_cloud-netblocks3.googleusercontent.com, _cloud-netblocks4.googleusercontent.com,
_cloud-netblocks5.googleusercontent.com
Next, look up the DNS records associated with those domains one at a time (Figure 3):
$ nslookup -q=TXT _cloud-netblocks1.googleusercontent.com 8.8.8.8
$ nslookup -q=TXT _cloud-netblocks2.googleusercontent.com 8.8.8.8
$ nslookup -q=TXT _cloud-netblocks3.googleusercontent.com 8.8.8.8
$ nslookup -q=TXT _cloud-netblocks4.googleusercontent.com 8.8.8.8
$ nslookup -q=TXT _cloud-netblocks5.googleusercontent.com 8.8.8.8
Figure 3 Commands
The above results will return a list of IP Ranges and once consolidated, these will be the GCP IP ranges used.
Note: GCP does not provide any mapping between the IP range to their corresponding zones.
If you require further assistance regarding this, please contact the Symphony Support team at support@symphony.com
As per the FAQ here, Google Cloud Platform (GCP) uses a large range of IP addresses, which change over time. For historical reasons, GCP publishes its list of public IP addresses in an SPF record for_cloud-netblocks.googleusercontent.com.