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NAT IP POOL!

DISCUSSION Blizzards 2 participants 3 messages Dec 5, 2002

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Blizzards

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#0 lore raw

Hi list!

Those are my questions:

A)I need to SNAT a subnet 192.168.1.0/24 with 172.16.1.0/24.
I use this tule:
iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -j SNAT --to 172.16.1.0/24
This is ok, but when i nat an address, i must create an ip alias on ethn an my nat box for this to work. Ok.
When i use few address no problem at all, but using a pool of address (a subnet or an interval of ip address), i must create 254 aliases for the interface or there was a better method? B)Iptables Nat a pool of address with 1:1 method like cisco nat?
If yes, when no more address 1:1 are avaiable for connections, can i
se a PAT address like cisco nat?
Or iptables works differently balancing the load of ip address used?

Thanks in advance
Giulius.

#1 lore raw
Quoted 5 lines · Blizzards

Hi list!

Those are my questions:

Quoted 13 lines

A)I need to SNAT a subnet 192.168.1.0/24 with 172.16.1.0/24.
I use this tule:
iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -j SNAT --to 172.16.1.0/24 This is ok, but when i nat an address, i must create an ip alias on ethn an my nat box for this to work. Ok.
When i use few address no problem at all, but using a pool of address (a subnet or an interval of ip address), i must create 254 aliases for the interface or there was a better method?
B)Iptables Nat a pool of address with 1:1 method like cisco nat? If yes, when no more address 1:1 are avaiable for connections, can i se a PAT address like cisco nat?
Or iptables works differently balancing the load of ip address used?

Hi,

You probably want to look at the NETMAP target that is in patch-o-matic. SNAT and DNAT targets will do some loadbalancing. You'll get weird results with your setup.

With NETMAP you can do source NAT and destination NAT of whole subnets with a strict 1:1 mapping.

Regards,
Filip

author
#2 lore raw
Quoted 11 lines

Hi,

You probably want to look at the NETMAP target that is in patch-o-matic. SNAT and DNAT targets will do some loadbalancing. You'll get weird results with your setup.

With NETMAP you can do source NAT and destination NAT of whole subnets with a strict 1:1 mapping.

Ok, but if i need to SNAT a whole subnet 192.168.1.0/24 with a short pool of address like 172.16.1.1-172.16.1.10 with a strict 1:1 only 10 ip are natted.
NETMAP give me the ability to write down a PAT address for the rest of connections?
Or for short pool it's better to setup interfaces aliases?

Thanks.
Giulius.

Quoted 7 lines

Regards,
Filip