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The behavior of /24 vs /32 addresses when using iptables
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this post was submitted on 03 Mar 2026
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Thank you very much! :)
Interesting why
iptablesbehaves like that though. Because, if I understand it correctly, specifying any address between 192.168.1.[0...255]/24 will result in all addresses in that range to be accepted? So, the only way to actually single out one host is to use the mask /32...?Yes, exactly. The convention is to use the lowest address in the range (e.g. 192.168.1.0/24), since you're allowing a range of addresses rather than a single one.
The reason to do this is that many firewall rules will be based on sets of addresses - you might want to allow traffic from any device in your local network without having to add individual rules for each
Tomorrow, at work, I'm gonna brag about what I have learned here today, until my colleagues' ears fall off.
Thanks again! :)