Re: [cobalt-users] Syntax (IP blocking) hosts.deny..?

[flash22@xxxxxxx]

On Thu, 1 Mar 2001, Craig Napier wrote:

> Is it possilbe to enter a range of IP's in the hosts.deny file without 
> writing each one on a sepearate line? For example if I wanted to block via 
> hosts.deny all IP's between
> 
> xxx.6.95.0 - xxx.6.95.255
> 
> how would I enter that?

There are nice examples in the man page;)

For ranges that are conveniently on octet boundries, all you need to do is
specify the beginning with a trailing dot

eg

ALL: xxx.6.95.

will block all services for all address from xxx.6.95.0 - xxx.6.95.255

ALL: xxx.6.  will block all 65536 addresses from xxx.8.0.0 to
xxx.6.255.255   etc

For address ranges that aren't conveniently in nice multiples you have  to
use a netmask...

This does the same thing , albiet messier

ALL: xxx.6.95.0/255.255.255.0

To match 512 addresses , remove 1 bit

 /255.255.254.0

(your address isn't aligned on 512 boundry tho, so you would need 2 lines
to map 512 addresses in any case [eg 95 is odd])

beware typos in this file, you can kill yourself -)

gsh

(There are earlier posts about this with links to programs to help figure
out netmask/range values )