KPF rule specification of remote subnet address and mask

Jul 15, 2007 4 Replies

I'm using KPF 2.1.5, specifying the remote endpoint for a rule. I've read wikipedia's page on subnetworks. The KPF rule window asks for a network address and a network mask. My understanding is that a network address 123.234.321.432 and network mask 255.255.255.0 specifies a network address 123.234.321, which includes all devices with IP addresses 123.234.321.0 to 123.234.321.255. Is this correct? I wouldn't normally seek a sanity check on something that seems quite obvious, except that it seems like a strange way to specify the address range (in 2 separate pieces) when you could just as easily say 123.234.321.xxx. Thanks.


is not an IP-Address. There can't be any quad bigger than 255.

More or less.

It is a very similar thing.

Cheers, Jens

but only for /24 networks (netmask 255.255.255.0)

BTW: I know that you know. ;)

I'd recommend that the OP should read some documents describing ipv4.

Wolfgang

Egad! My bad! Thanks for the correction. I knew I should have used letters instead of decimal numbers.

123.234.321.xxx.

Thanks!

Have done so, some time ago. It just seems like such an indirect way of specifying a mask that I thought I'd make sure, especially for a firewall rule. Coming from a DSP digital circuit design background, it seems much more natural to specify a network address with don't-care bits in the LSBs that aren't part of the network address. Not 2 pieces of data, one being a mask and the other containing the network address and some irrelevant LSBs of arbitrary value. I suppose the latter is quite useful, though, if one wants to imply an extraction of the network address from the full 32-bit address. Let the computer do the work.

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