121.15.4 is a class C of IPs

Sample IPs from the class C 121.15.4

121.15.4.112	View precise location of 121.15.4.112 on the map!
121.15.4.72	View precise location of 121.15.4.72 on the map!
121.15.4.65	View precise location of 121.15.4.65 on the map!
121.15.4.151	View precise location of 121.15.4.151 on the map!
121.15.4.160	View precise location of 121.15.4.160 on the map!
121.15.4.55	View precise location of 121.15.4.55 on the map!
121.15.4.102	View precise location of 121.15.4.102 on the map!
121.15.4.201	View precise location of 121.15.4.201 on the map!
121.15.4.179	View precise location of 121.15.4.179 on the map!
121.15.4.180	View precise location of 121.15.4.180 on the map!
121.15.4.197	View precise location of 121.15.4.197 on the map!

10 Random IPs

170.27.101.163	Find precise map location of 170.27.101.163
149.235.98.160	Find precise map location of 149.235.98.160
155.215.164.87	Find precise map location of 155.215.164.87
175.26.103.233	Find precise map location of 175.26.103.233
220.136.180.100	Find precise map location of 220.136.180.100
88.25.20.228	Find precise map location of 88.25.20.228
181.91.65.134	Find precise map location of 181.91.65.134
32.138.100.129	Find precise map location of 32.138.100.129
153.24.198.64	Find precise map location of 153.24.198.64
86.230.215.119	Find precise map location of 86.230.215.119
27.64.250.221	Find precise map location of 27.64.250.221

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