IPFW blocking ip ranges

[Jos Chrispijn]

Can you tell me how to block in ipfw a certain ip range in one line, like 1.184.192.0 - 1.184.255.255
Thanks.

[Paul Procacci]

On Fri, Jun 7, 2024 at 1:41 PM Jos Chrispijn <jo...@cloudzeeland.nl> wrote:

Can you tell me how to block in ipfw a certain ip range in one line, like 1.184.192.0 - 1.184.255.255
Thanks.

ipfw add <rulenum> deny all from 1.184.0.0/18 to any

Replace <rulenum> accordingly.

~Paul

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[Paul Procacci]

Ack!!!  abort abort!

ipfw add <rulenum> deny all from 1.184.192.0/18 to any

There ya go.

[Brett Glass]

IPFW has the ability to block subnets (ranges that can be matched with a
base address and bitmask), e.g. 1.184.192.0/18, with just one pattern within
a rule. Arbitrary ranges and discontiguous sets that can't be matched that
way can use:

* An "or block" (several patterns enclosed within braces and separated by "or");

* Multiple rules; or

* An "address set" (a subnet specification followed by a list of addresses within
a subnet that's /24 or smaller).

The IPFW man page gives a grammar and shows examples. Search for "addr-list"
within the page to find the right section.

--Brett