Hi,

>> I prefer to use rules like
>> DNS(ACCEPT)    ext    $FW
>>
>> The built in macros, mostly, insure that you get all the requisite ports
>> opened to do what you need.

Finally had a minute to test this, and realized that $FW evaluates to
0/0. Is that correct?

If so, that's allowing any server on the Internet to query any box on
my network for DNS, correct?

# iptables -nL|grep 53
DROP       udp  --  0.0.0.0/0            0.0.0.0/0           udp
spt:53 /* Late DNS Replies */
DROP       udp  --  0.0.0.0/0            0.0.0.0/0           udp
spt:53 /* Late DNS Replies */
ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0         udp dpt:53
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0          tcp dpt:53

Where do the "Late DNS Replies" come from? I don't see that reflected
in the DNS macro:

###############################################################################
#ACTION SOURCE  DEST    PROTO   DEST    SOURCE  RATE    USER/
#                               PORT(S) PORT(S) LIMIT   GROUP
PARAM   -       -       udp     53
PARAM   -       -       tcp     53

I know there is a very specific set of rules for DNS that can be used
to minimize attack. It's outlined in the OReilly Firewall book, but
it's an arduous process trying to create every specific rule.

Any help would be greatly appreciated.

Thanks,
Alex

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