121.51.13 is a class C of IPs

Sample IPs from the class C 121.51.13

121.51.13.45	View precise location of 121.51.13.45 on the map!
121.51.13.129	View precise location of 121.51.13.129 on the map!
121.51.13.132	View precise location of 121.51.13.132 on the map!
121.51.13.238	View precise location of 121.51.13.238 on the map!
121.51.13.225	View precise location of 121.51.13.225 on the map!
121.51.13.254	View precise location of 121.51.13.254 on the map!
121.51.13.31	View precise location of 121.51.13.31 on the map!
121.51.13.3	View precise location of 121.51.13.3 on the map!
121.51.13.26	View precise location of 121.51.13.26 on the map!
121.51.13.112	View precise location of 121.51.13.112 on the map!
121.51.13.211	View precise location of 121.51.13.211 on the map!

10 Random IPs

44.200.229.174	Find precise map location of 44.200.229.174
5.123.216.116	Find precise map location of 5.123.216.116
139.221.182.217	Find precise map location of 139.221.182.217
103.20.146.242	Find precise map location of 103.20.146.242
237.131.134.53	Find precise map location of 237.131.134.53
170.198.127.49	Find precise map location of 170.198.127.49
129.203.120.244	Find precise map location of 129.203.120.244
240.168.218.17	Find precise map location of 240.168.218.17
24.207.138.48	Find precise map location of 24.207.138.48
132.149.66.18	Find precise map location of 132.149.66.18
174.114.82.71	Find precise map location of 174.114.82.71

TestURI.org is a free web-sniffer.net alternative. It alows you to send custom HTTP request and check the HTTP response.