How to allow private connectivity across organizations(GCP)?

It's interesting, when you would like to allow private connectivity across two VPC networks that they belong to the different project/organization on Google Cloud Platform (GCP).

As google document that we can use VPC Network Peering? VPC Network Peering is a decentralized or distributed approach to multi-project networking. Additional, it works with Compute Engine, Kubernetes Engine,and App Engine flexible environments.

I did a lab about Virtual Private Cloud (VPC) Network Peering. There shows to do VPC Network Peering between VPC networks in the same project. So, I would like to see how it works on across organizations.

Example: On My Organization (my project), I would like to connect server (Private IP Address) on another Organization (another project).

As a subnet CIDR prefix in one peered VPC network cannot overlap with a subnet CIDR prefix in another peered network. So, both VPC networks must have the different CIDR prefix.

My Organization [myproject] {ubuntu-test, default/10.146.0.2} <======> No organization [qwiklabs-gcp***]{privatenet-us-vm/172.16.0.2}

On No organization [qwiklabs-gcp***]: VPC network name is "privatenet".

VPC:
Firewall:


My Organization [myproject]: I used "default" VPC and default firewall.

Then, starting to create "VPC Network Peering".

- To create "VPC Network Peering" on myproject: Networking => "VPC network" => "VPC network peering".
Click "Create Peering Connection".  name = "peering-to-lab".
Note: you must know Project ID and VPC network name for network destination.

It should show "Waiting for peer network to connect".

-  To create "VPC Network Peering" on another Project: On No organization [qwiklabs-gcp***], "Create Peering Connection".  name = "peering-to-mygcp".

After clicking "Create". It should show "Connected" on both projects (if configuration corrects) like.

On myproject:

- Finally, test connection: ssh to my vm and test (ssh) connection to {privatenet-us-vm/172.16.0.2}.
Note: (as firewall allow icmp/ssh). No need to do on firewall.

opun@ubuntu-test:~$ ssh 172.16.0.2
opun@172.16.0.2's password:
Linux privatenet-us-vm 4.9.0-8-amd64 #1 SMP Debian 4.9.110-3+deb9u4 (2018-08-21) x86_64
The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Wed Sep 19 06:22:05 2018 from 10.146.0.2
Could not chdir to home directory /home/opun: No such file or directory
$ w
 06:22:55 up 43 min,  2 users,  load average: 0.00, 0.00, 0.00
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
opun     pts/1    10.146.0.2       06:22    1.00s  0.00s  0.00s w ************

Reference: https://cloud.google.com/vpc/docs/vpc-peering