81.51.39 is a class C of IPs

Sample IPs from the class C 81.51.39

81.51.39.14	View precise location of 81.51.39.14 on the map!
81.51.39.226	View precise location of 81.51.39.226 on the map!
81.51.39.220	View precise location of 81.51.39.220 on the map!
81.51.39.148	View precise location of 81.51.39.148 on the map!
81.51.39.175	View precise location of 81.51.39.175 on the map!
81.51.39.54	View precise location of 81.51.39.54 on the map!
81.51.39.140	View precise location of 81.51.39.140 on the map!
81.51.39.183	View precise location of 81.51.39.183 on the map!
81.51.39.209	View precise location of 81.51.39.209 on the map!
81.51.39.89	View precise location of 81.51.39.89 on the map!
81.51.39.52	View precise location of 81.51.39.52 on the map!

10 Random IPs

197.121.68.2	Find precise map location of 197.121.68.2
20.235.199.68	Find precise map location of 20.235.199.68
116.195.238.93	Find precise map location of 116.195.238.93
35.21.158.120	Find precise map location of 35.21.158.120
54.250.32.153	Find precise map location of 54.250.32.153
228.190.130.209	Find precise map location of 228.190.130.209
121.233.13.240	Find precise map location of 121.233.13.240
42.115.230.19	Find precise map location of 42.115.230.19
173.192.187.170	Find precise map location of 173.192.187.170
192.31.192.177	Find precise map location of 192.31.192.177
106.166.6.245	Find precise map location of 106.166.6.245

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