its the a,b,c network class increments are show below

./ipiterator.pl 17 2.29.140.250 172.29.141.4

checking ip: 172.29.140.250 ping success
checking ip: 172.29.140.251 ping success
checking ip: 172.29.140.252
checking ip: 172.29.140.253 ping success
checking ip: 172.29.140.254
checking ip: 172.29.<b>140</b>.255
checking ip: 172.29.<b>141</b>.0
checking ip: 172.29.141.1
checking ip: 172.29.141.2

./ipcheck.pl 172.254.254.254 173.0.0.4

checking ip: 172.254.254.254
checking ip: 172.<b>254</b>.254.255
checking ip: <b>173</b>.0.0.0
checking ip: 173.0.0.1 ping success
checking ip: 173.0.0.2 ping success
checking ip: 173.0.0.3
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