[wrkronmiller]

Correct, but in this case, it sounds like you didn't need to use the ISP router as your VPN gateway.

If I understand the DNS rebinding attack reference correctly, you could be running the VPN software on your desktop/laptop and still have your IP revealed by your ISP router.

[lxgr]

Arguably, a setup using a VPN for anonymity purposes is badly flawed if it allows traffic to anything but the VPN gateway. This includes the local network.

Mediocre home appliances or (as in this case) ISP CPEs can easily deanonymize you.

[mindslight]

Yes, but you do want deliberate access to specific services on the local network. Mainly NFS exports and the like.