@vladone: "If i understand corectly with redirect_address i can forward an given
public ip (commonly an alias on pubic interface) to an internal ip
(private). I dont know if this is good for what i want.
More exactly description for what i want:
My private network is: 83.161.120.155/24
I have (example) public ip: 83.161.120.155, 83.161.120.155 and 83.161.120.155
I want:
ip's: 83.161.120.155-20 out(tranlated) with 83.161.120.155
ip's: 83.161.120.155-30 out with 83.161.120.155
 and so."
    @lists: "<quote>
If you wanted a one-to-one mapping between public and private IP's, then you 
could use redirect_address.  For what you describe above, though, the best 
approach may be to run multiple instances of natd and split up the traffic 
with ipfw.
Sample setup
In /etc/services:
natd	8668
natd2	8669
natd3	8670
In a natd script (I don't think the rc scripts support multiple instances of 
natd):
natd -a 83.161.120.155 -p natd
natd -a 83.161.120.155 -p natd2
natd -a 83.161.120.155 -p natd3
And in an ipfw script:
add divert natd3 all from 83.161.120.155,83.161.120.155,83.161.120.155 to any \
	via ${external_interface}
add skipto 10000 all from 83.161.120.155,83.161.120.155,83.161.120.155 to any \
add divert natd2 all from 83.161.120.155,83.161.120.155,83.161.120.155 to any \
	via ${external_interface}
add skipto 10000 all from 83.161.120.155,83.161.120.155,83.161.120.155 to any \
	via ${external_interface}
add divert natd all from any to any via ${external_interface}
add 10000 allow all from any to any via lo0
...
So you'd give a name to each divert port you want to use in /etc/services 
(8668 is already there), run an instance of natd for each external alias, 
and use comma-separated lists of IP addresses and skipto's in ipfw to 
direct the traffic appropriately.  Notice that I made the last one a 
default rather than specifying its addresses explicitly.  Depending on your 
needs you may want to do something similar.
JN"
    @lists: "<quote>
It occured to me you may also need rules for the other direction, a la:
add divert natd3 all from any to 83.161.120.155 via ${extarnal_interface}
Can someone correct me if I'm wrong?
JN"
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