currently I am running on localhost...so according only "127.0.0.1"should be pingable on port "3000". But I get this IP "127.115.99.245" also pingable as TRUE

Yes, that's perfectly ok. localhost has a whole Class-A subnet assigned in IPv4, 16.7 million addresses, all starting with "127.", all just for the machine you are currently working with. Yes, that's a big waste of IP addresses, but it's an old decision that can't be changed now.

Alexander