hosts.allowのサブネット書き方

hosts.allow サブネット書き方

hosts.allowのサブネットの書き方は、長い間 n.n.n.n/m.m.m.mと書かなきゃいけないのかなって思ってたけど、n.n.n.n/mm方式でもいいみたい。

hosts.allow の man より

An expression of the form `n.n.n.n/m.m.m.m´ is interpreted as a`net/mask´ pair. An IPv4 host address is matched if `net´ is
 equal to the bitwise AND of the address and the `mask´. Forexample, the net/mask pattern `131.155.72.0/255.255.254.0´matches every address in the range `131.155.72.0´ through`131.155.73.255´. `255.255.255.255´ is not a valid mask value,so a single host can be matched just by its IP.

An expression of the form `n.n.n.n/mm' is interpreted as a `net/masklength' pair, where `mm' is the number of consecutive `1' bits in the netmask applied to the `n.n.n.n' address.

って書いてある。だから

125.193.92.210/255.255.255.255

でも

125.193.92.210/32

こちらでもどっちでもいいって事だね。