Need to block ?
Adalbert Prokop
adalbert.prokop at gmx.de
Sat Jun 30 12:40:55 UTC 2007
Bob Goodwin - W2BOD wrote on Saturday 30 June 2007:
> What is the correct notation for blocking a range of addresses in my
> router?
> If I block 64.18.5.13 it simply moves up to 64.18.5.14.
> I thought the proper way to do it was 64.18.5.0/255 but obviously
> that's wrong or at least doesn't work for me.
You are mixing up mask notations. There are two of them
1) dottet decimal notation, like 255.255.255.0
2) CCIT notation, like 192.168.1.0/24
192.168.1.0/24 says "the first 24 bits of the mask are ones" and is
255.255.255.0 in decimal notation.
255.255.255.0 = 11111111 11111111 11111111 00000000
--------------------------
24 ones
What you said was "the first 255 bits of the mask are ones" and that is
nonsense, since the mask is only 32 bit long (4 bytes).
CCIT notation is a little more limited than dottet notation, since you
cannot create a mask like
11111111 11111111 10101010 00000000 = 255.255.170.0
But in practice it is irrelevant, since there is (almost?) no reason to
use such masks.
--
bye,
Adalbert
pseudo-user on a pseudo-terminal
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