NTH

NTH

[Pedro Drimel Neto]

Hi all,

I'm using the nth module for each connection it change of IP.
The scenario is:
--------------              -------------
| Server with | ------ > |    Server    |
|      NTH     |               |   Master    |
--------------              -------------
So, the users connect to "Server with NTH" and the .bashrc of the user has a 
ssh to "Server Master".
On "Server with NTH" has an interface, eth0, with 2 logics, eth0:0 and 
eth0:1
eth0: 10.0.0.2
eth0:0 10.0.0.3
eth0:1: 10.0.0.4
Above are the rules on "Server with NTH"
iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth --counter 
7 --every 3 --packet 0 -j SNAT --to-source 10.0.0.2
iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth --counter 
7 --every 3 --packet 1 -j SNAT --to-source 10.0.0.3
iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth --counter 
7 --every 3 --packet 2 -j SNAT --to-source 10.0.0.4

So, at each connection to "Server Master" the IP is changed.
As NTH support only packet 0, 1 and 2 and I need to more IPs to be changed, 
if I add more a interface does it work ?
Thanks a lot.

Regards. 

Re: NTH

[Stephan Scholz]

Yes, that should work. Simply increase the "every" number and add a new rule.

Example for 4 hosts:

iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth --counter 7 --every 4 --packet 0 -j SNAT --to-source 10.0.0.2
iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth --counter 7 --every 4 --packet 1 -j SNAT --to-source 10.0.0.3
iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth --counter 7 --every 4 --packet 2 -j SNAT --to-source 10.0.0.4
iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth --counter 7 --every 4 --packet 3 -j SNAT --to-source 10.0.0.5

Stephan

Pedro Drimel Neto wrote:
> Hi all,
> 
> I'm using the nth module for each connection it change of IP.
> The scenario is:
> --------------              -------------
> | Server with | ------ > |    Server    |
> |      NTH     |               |   Master    |
> --------------              -------------
> So, the users connect to "Server with NTH" and the .bashrc of the user
> has a ssh to "Server Master".
> On "Server with NTH" has an interface, eth0, with 2 logics, eth0:0 and
> eth0:1
> eth0: 10.0.0.2
> eth0:0 10.0.0.3
> eth0:1: 10.0.0.4
> Above are the rules on "Server with NTH"
> iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth
> --counter 7 --every 3 --packet 0 -j SNAT --to-source 10.0.0.2
> iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth
> --counter 7 --every 3 --packet 1 -j SNAT --to-source 10.0.0.3
> iptables -t nat -A POSTROUTING -o eth0 -d "Server Master" -m nth
> --counter 7 --every 3 --packet 2 -j SNAT --to-source 10.0.0.4
> 
> So, at each connection to "Server Master" the IP is changed.
> As NTH support only packet 0, 1 and 2 and I need to more IPs to be
> changed, if I add more a interface does it work ?
> Thanks a lot.
> 
> Regards.
> 


-- 

Stephan Scholz

sscholz@astaro.com | Development
Astaro AG | www.astaro.com | Phone +49-721-25516-0
Fax +49-721-25516-200
Amalienbadstraße 36 / Bau 33a | 76227 Karlsruhe | Germany

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