Re: help on firewall

[Paul Miller <pmiller@jove.acs.unt.edu>]

iodine wrote:
> 
> When using ip_masquerading, I have seen a friend block machines on his
> internal network from using http/ftp/telnet to any address on the outside
> using ipfwadm. ie 192.168.1.5 not allowed to use ftp(21), telnet(32) and
> http(80) to anywhere by using 0.0.0.0 in the command line or something
> similar. Not sure on the exact command line, but have seen him do it. And it
> worked well.
> 
> /etc/hosts.allow & /etc/hosts.deny is for blocking services/ips coming in..
> not going out. or am I wrong?
> 
I'm sorry. I read below that you wanted to prevent ftp and telnet access
wo your mail server. To prevent outbound ftp and telnet from a specific
host try

ipfwadm -F -a deny -P tcp -S 192.168.1.5/32 -D 0.0.0.0/0 telnet ftp

> >Wilson Tuma wrote:
> >
> >> Hi
> >>
> >> How do I use ipfwadm to prevent  all the users of my local network from
> >> doing ftp and telnet to my mail server while allowing only  two other
> >> systems the same network from beign able to telnet or ftp to the mail
> >> server.
> >
> >ipfwadm will only filter between networks. You need to take a look at
> /etc/hosts.allow
> >and /etc/hosts.deny. There is a man page for these files.
> >
 >--


-- 
Paul Miller
pmiller@jove.acs.unt.edu