3 outside networks

3 outside networks

[Srinath Mantripragada]

Hi,

I need some help with iptables and SNAT.


I have one inside net 172.16.0.0/24  and 3 outside nets  10.28.0.0/16 ,
   172.18.0.0/24 and Internet.
The 3 nets are routed by one router that i do not have control.

I have valid internet Addresses and i want to use NAT with one of them
but not for 10.28 and 172.18 networks.


i tried this:

iptables -t nat -I POSTROUTING -o eth1 -d ! 10.28.0.0/16 -j SNAT --to
MY.VALID.ADDR
iptables -t nat -I POSTROUTING -o eth1 -d ! 172.18.0.0/24 -j SNAT
--to MY.VALID.ADDR


I guess that i need something like :   "-d  ! 10.28.0.0/16  OR ! 
172.18.0.0./24"
but i dont  know how  to do that.


Can someone helpme ?


Thanks

Re: 3 outside networks

[Antony Stone]

On Monday 17 June 2002 3:34 pm, Srinath Mantripragada wrote:

> I have one inside net 172.16.0.0/24  and 3 outside nets  10.28.0.0/16 ,
>    172.18.0.0/24 and Internet.
> The 3 nets are routed by one router that i do not have control.
>
> I have valid internet Addresses and i want to use NAT with one of them
> but not for 10.28 and 172.18 networks.
>
> I guess that i need something like :   "-d  ! 10.28.0.0/16  OR !
> 172.18.0.0./24"
> but i dont  know how  to do that.

Try this:

iptables -A POSTROUTING -t nat -d 10.28.0.0/16 -j ACCEPT
iptables -A POSTROUTING -t nat -d 172.18.0.0/24 -j ACCEPT
iptables -A POSTROUTING -t nat -j SNAT --to a.b.c.d

 

Antony.

Re: 3 outside networks

[Antony Stone]

On Monday 17 June 2002 7:13 pm, Antony Stone wrote:

> On Monday 17 June 2002 3:34 pm, Srinath Mantripragada wrote:
> > I have one inside net 172.16.0.0/24  and 3 outside nets  10.28.0.0/16 ,
> >    172.18.0.0/24 and Internet.
> > The 3 nets are routed by one router that i do not have control.
> >
> > I have valid internet Addresses and i want to use NAT with one of them
> > but not for 10.28 and 172.18 networks.
> >
> > I guess that i need something like :   "-d  ! 10.28.0.0/16  OR !
> > 172.18.0.0./24"
> > but i dont  know how  to do that.
>
> Try this:
>
> iptables -A POSTROUTING -t nat -d 10.28.0.0/16 -j ACCEPT
> iptables -A POSTROUTING -t nat -d 172.18.0.0/24 -j ACCEPT
> iptables -A POSTROUTING -t nat -j SNAT --to a.b.c.d

Ooops !   That last one should inlcude the interface name too:

iptables -A POSTROUTING -t nat -o eth1 -j SNAT --to a.b.c.d

 

Antony.