138.255.121 is a class C of IPs

Sample IPs from the class C 138.255.121

138.255.121.71	View precise location of 138.255.121.71 on the map!
138.255.121.134	View precise location of 138.255.121.134 on the map!
138.255.121.92	View precise location of 138.255.121.92 on the map!
138.255.121.69	View precise location of 138.255.121.69 on the map!
138.255.121.152	View precise location of 138.255.121.152 on the map!
138.255.121.82	View precise location of 138.255.121.82 on the map!
138.255.121.228	View precise location of 138.255.121.228 on the map!
138.255.121.8	View precise location of 138.255.121.8 on the map!
138.255.121.174	View precise location of 138.255.121.174 on the map!
138.255.121.11	View precise location of 138.255.121.11 on the map!
138.255.121.186	View precise location of 138.255.121.186 on the map!

10 Random IPs

87.174.162.232	Find precise map location of 87.174.162.232
210.70.155.63	Find precise map location of 210.70.155.63
162.137.148.204	Find precise map location of 162.137.148.204
28.115.20.74	Find precise map location of 28.115.20.74
56.246.254.123	Find precise map location of 56.246.254.123
82.133.43.83	Find precise map location of 82.133.43.83
203.235.151.88	Find precise map location of 203.235.151.88
38.205.16.183	Find precise map location of 38.205.16.183
16.45.107.215	Find precise map location of 16.45.107.215
21.61.209.109	Find precise map location of 21.61.209.109
137.157.98.181	Find precise map location of 137.157.98.181

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