OK<br>
ip=192.168.0.1 ret=1<br>
ip=0.0.0.0 ret=1<br>
ip=255.255.255.255 ret=1<br>
NG<br>
ip=192168.0.1 ret=<br>
ip=01.168.0.1 ret=<br>
ip=1.2168.0.1 ret=<br>
ip=1.168..1 ret=<br>
ip=1.168.a0.1 ret=<br>
ip=1.168.00.1 ret=<br>
ip=192.168.0.256 ret=<br>
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