163.81.187 is a class C of IPs

Sample IPs from the class C 163.81.187

163.81.187.113	View precise location of 163.81.187.113 on the map!
163.81.187.43	View precise location of 163.81.187.43 on the map!
163.81.187.88	View precise location of 163.81.187.88 on the map!
163.81.187.218	View precise location of 163.81.187.218 on the map!
163.81.187.44	View precise location of 163.81.187.44 on the map!
163.81.187.64	View precise location of 163.81.187.64 on the map!
163.81.187.229	View precise location of 163.81.187.229 on the map!
163.81.187.15	View precise location of 163.81.187.15 on the map!
163.81.187.70	View precise location of 163.81.187.70 on the map!
163.81.187.170	View precise location of 163.81.187.170 on the map!
163.81.187.169	View precise location of 163.81.187.169 on the map!

10 Random IPs

239.127.171.176	Find precise map location of 239.127.171.176
155.186.114.220	Find precise map location of 155.186.114.220
157.98.191.152	Find precise map location of 157.98.191.152
136.27.37.227	Find precise map location of 136.27.37.227
158.160.196.211	Find precise map location of 158.160.196.211
97.147.246.89	Find precise map location of 97.147.246.89
221.188.131.6	Find precise map location of 221.188.131.6
169.152.196.139	Find precise map location of 169.152.196.139
113.122.170.209	Find precise map location of 113.122.170.209
239.156.93.49	Find precise map location of 239.156.93.49
86.178.90.163	Find precise map location of 86.178.90.163

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