You use IPv4 protocol.
http://www.polarhome.com supports IPv6 too.

Hostname=
IP address=54.81.105.205

ISP information:





Connection information:
Connection=close
User agent=CCBot/2.0 (http://commoncrawl.org/faq/)
Remote port=53848
Server port=80
Protocol=HTTP/1.1
Language=
Request=GET

nslookup response:
Server:		192.168.10.36
Address:	192.168.10.36#53

Non-authoritative answer:
205.105.81.54.in-addr.arpa	name = ec2-54-81-105-205.compute-1.amazonaws.com.

Authoritative answers can be found from:
81.54.in-addr.arpa	nameserver = x2.amazonaws.com.
81.54.in-addr.arpa	nameserver = x3.amazonaws.org.
81.54.in-addr.arpa	nameserver = pdns1.ultradns.net.
81.54.in-addr.arpa	nameserver = x1.amazonaws.com.
81.54.in-addr.arpa	nameserver = x4.amazonaws.org.
x1.amazonaws.com	internet address = 156.154.64.10
x2.amazonaws.com	internet address = 156.154.65.10
x3.amazonaws.org	internet address = 208.78.71.31
x4.amazonaws.org	internet address = 204.13.251.31
pdns1.ultradns.net	internet address = 204.74.108.1
pdns1.ultradns.net	has AAAA address 2001:502:f3ff::1

dig -x response:

; <<>> DiG 9.8.4-P1-RedHat-9.8.4-3.P1.fc16 <<>> -x 54.81.105.205
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22986
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 5, ADDITIONAL: 6

;; QUESTION SECTION:
;205.105.81.54.in-addr.arpa.	IN	PTR

;; ANSWER SECTION:
205.105.81.54.in-addr.arpa. 300	IN	PTR	ec2-54-81-105-205.compute-1.amazonaws.com.

;; AUTHORITY SECTION:
81.54.in-addr.arpa.	3600	IN	NS	x1.amazonaws.com.
81.54.in-addr.arpa.	3600	IN	NS	x2.amazonaws.com.
81.54.in-addr.arpa.	3600	IN	NS	x3.amazonaws.org.
81.54.in-addr.arpa.	3600	IN	NS	x4.amazonaws.org.
81.54.in-addr.arpa.	3600	IN	NS	pdns1.ultradns.net.

;; ADDITIONAL SECTION:
x1.amazonaws.com.	686	IN	A	156.154.64.10
x2.amazonaws.com.	686	IN	A	156.154.65.10
x3.amazonaws.org.	686	IN	A	208.78.71.31
x4.amazonaws.org.	686	IN	A	204.13.251.31
pdns1.ultradns.net.	980	IN	A	204.74.108.1
pdns1.ultradns.net.	980	IN	AAAA	2001:502:f3ff::1

;; Query time: 18 msec
;; SERVER: 192.168.10.36#53(192.168.10.36)
;; WHEN: Fri Jun 22 01:22:23 2018
;; MSG SIZE  rcvd: 320

dig A response:

; <<>> DiG 9.8.4-P1-RedHat-9.8.4-3.P1.fc16 <<>> A 54.81.105.205
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 39095
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;54.81.105.205.			IN	A

;; AUTHORITY SECTION:
.			10800	IN	SOA	a.root-servers.net. nstld.verisign-grs.com. 2018062102 1800 900 604800 86400

;; Query time: 39 msec
;; SERVER: 192.168.10.36#53(192.168.10.36)
;; WHEN: Fri Jun 22 01:22:23 2018
;; MSG SIZE  rcvd: 106