18.99.81 is a class C of IPs

Sample IPs from the class C 18.99.81

18.99.81.255	View precise location of 18.99.81.255 on the map!
18.99.81.244	View precise location of 18.99.81.244 on the map!
18.99.81.67	View precise location of 18.99.81.67 on the map!
18.99.81.67	View precise location of 18.99.81.67 on the map!
18.99.81.56	View precise location of 18.99.81.56 on the map!
18.99.81.179	View precise location of 18.99.81.179 on the map!
18.99.81.50	View precise location of 18.99.81.50 on the map!
18.99.81.136	View precise location of 18.99.81.136 on the map!
18.99.81.48	View precise location of 18.99.81.48 on the map!
18.99.81.98	View precise location of 18.99.81.98 on the map!
18.99.81.104	View precise location of 18.99.81.104 on the map!

10 Random IPs

163.15.214.28	Find precise map location of 163.15.214.28
132.232.73.230	Find precise map location of 132.232.73.230
143.85.50.111	Find precise map location of 143.85.50.111
37.91.11.194	Find precise map location of 37.91.11.194
219.55.40.136	Find precise map location of 219.55.40.136
11.25.91.88	Find precise map location of 11.25.91.88
108.21.34.144	Find precise map location of 108.21.34.144
1.15.45.148	Find precise map location of 1.15.45.148
254.167.79.196	Find precise map location of 254.167.79.196
129.196.56.25	Find precise map location of 129.196.56.25
191.76.86.131	Find precise map location of 191.76.86.131

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