137.21.5 is a class C of IPs

Sample IPs from the class C 137.21.5

137.21.5.54	View precise location of 137.21.5.54 on the map!
137.21.5.48	View precise location of 137.21.5.48 on the map!
137.21.5.38	View precise location of 137.21.5.38 on the map!
137.21.5.75	View precise location of 137.21.5.75 on the map!
137.21.5.172	View precise location of 137.21.5.172 on the map!
137.21.5.55	View precise location of 137.21.5.55 on the map!
137.21.5.250	View precise location of 137.21.5.250 on the map!
137.21.5.202	View precise location of 137.21.5.202 on the map!
137.21.5.215	View precise location of 137.21.5.215 on the map!
137.21.5.173	View precise location of 137.21.5.173 on the map!
137.21.5.232	View precise location of 137.21.5.232 on the map!

10 Random IPs

62.209.70.57	Find precise map location of 62.209.70.57
88.21.174.208	Find precise map location of 88.21.174.208
144.202.232.231	Find precise map location of 144.202.232.231
140.241.253.19	Find precise map location of 140.241.253.19
146.189.212.57	Find precise map location of 146.189.212.57
150.130.5.190	Find precise map location of 150.130.5.190
252.243.223.180	Find precise map location of 252.243.223.180
102.207.157.163	Find precise map location of 102.207.157.163
117.238.30.19	Find precise map location of 117.238.30.19
154.43.179.135	Find precise map location of 154.43.179.135
251.90.223.216	Find precise map location of 251.90.223.216

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