Wrong Use of Fallback IP(127.0.0.1) as fromIP in Ping message of Node Discovery Protocol

[learnerLj]

Our tool finds that a client Geth/v1.14.0-stable-87246f3c/linux-amd64/go1.22.2 sends node discovery Ping message whose fromIP is 127.0.0.1. But the second Ping of it shows the correct public IP. I guess the it is the NAT or the setupPortMapping that trigger the problem.