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Old 11-04-2002, 12:39 PM   #1
antken
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clearing up ipchains rules


hi,

i have just taken on yet another linux box ( bringing me to a grand total of 5 )

its setup is as follows: ( sorry about my ascii drawings )


{internet}
|
|
|
LINUX box -------- local clients ( as router )
|
|___win9x clients ( samba )


basically the ipchains rule book is over flowing with junk and its slowing it down so i want to clear it up.

i have flushed every thing out and i am now rebuilding

i want to block samba access to the box from outside will this line work:

Code:
ipchains -A input -s ! 192.168.0.0/16 -d 0/0 139 -p tcp -j DENY
what do you think? would that be ok?


thanks
antken

Last edited by antken; 11-04-2002 at 12:40 PM.
 
Old 11-04-2002, 01:15 PM   #2
akohlsmith
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How many network cards are on this? You should have a minimum of two (you can do it with one but I do not recommend it)

Then simply block tcp 135-139 on the external (WAN) interface.
 
Old 11-04-2002, 01:29 PM   #3
antken
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hi,


yes there are two nics in the box eth0 is the internal and the external nic is eth1

the internal ip is 192.168.0.0/16



thanks
 
Old 11-04-2002, 01:55 PM   #4
akohlsmith
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ok so iptables -I FORWARD 1 -p tcp -d 0/0 135-139 -j DENY
 
Old 11-04-2002, 02:14 PM   #5
antken
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would this work on an ipchains if i changed a few things around?

what does the '1' mean after the FORWARD ?
 
Old 11-04-2002, 02:28 PM   #6
akohlsmith
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It inserts the rule before the 1st entry in the FORWARD chain. I do that because if you have a masq line there you'll skip it.

I don't do it in INPUT or OUTPUT because this blocks packets going either way with one rule.
 
Old 11-04-2002, 03:26 PM   #7
peter_robb
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For the ipchains syntax have a look here...

http://www.linux.org/docs/ldp/howto/IPCHAINS-HOWTO.html

Regards,
Peter
 
  


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