Server machines behind Firewall

Server machines behind Firewall

[edwardspl]

Dear All,

Is there a sample ( nat scripts ) for the title ?

Edward.

Re: Server machines behind Firewall

[Jason Opperisano]

On Thu, Jan 06, 2005 at 12:14:16AM +0800, edwardspl@ita.org.mo wrote:
> Dear All,
> 
> Is there a sample ( nat scripts ) for the title ?

EXT_IF="eth0"
INT_IF="eth1"
SRV1="10.1.1.10"

iptables -t nat -A PREROUTING -i $EXT_IF -p tcp --dport 80 \
  -j DNAT --to-destination $SRV1

iptables -A FORWARD -i $EXT_IF -o $INT_IF -p tcp --syn -d $SRV1 \
  --dport 80 -j ACCEPT

rinse, repeat.

-j

--
"Ooh, they used nylon rope this time. It feels smooth against my skin,
 almost sensuous."
        --The Simpsons

Re: Server machines behind Firewall

[edwardspl]

Jason Opperisano wrote:

> On Thu, Jan 06, 2005 at 12:14:16AM +0800, edwardspl@ita.org.mo wrote:
> > Dear All,
> >
> > Is there a sample ( nat scripts ) for the title ?
>
> EXT_IF="eth0"
> INT_IF="eth1"
> SRV1="10.1.1.10"
>
> iptables -t nat -A PREROUTING -i $EXT_IF -p tcp --dport 80 \
>   -j DNAT --to-destination $SRV1

I want to know why needn't to define the original IP ( Public IP ) ?
eg :

iptables -t nat -A PREROUTING -i $EXT_IF -p tcp -s 202.175.xxx.xxx --dport
80 \
  -j DNAT --to-destination 192.168.xxx.xxx

Sorry, what useful about the following function ( command line ) ?

> iptables -A FORWARD -i $EXT_IF -o $INT_IF -p tcp --syn -d $SRV1 \
>   --dport 80 -j ACCEPT

In additional, if I want to setup a NAT ( 192.168.101.0/24 ) with a Server
machines ( 192.168.100.1 ) behind Firewall...
So, is there more than one sample ( nat scripts ) for reference ?

Edward.

Re: Server machines behind Firewall

[edwardspl]

Jason Opperisano wrote:

> On Thu, Jan 06, 2005 at 12:14:16AM +0800, edwardspl@ita.org.mo wrote:
> > Dear All,
> >
> > Is there a sample ( nat scripts ) for the title ?
>
> EXT_IF="eth0"
> INT_IF="eth1"
> SRV1="10.1.1.10"
>
> iptables -t nat -A PREROUTING -i $EXT_IF -p tcp --dport 80 \
>   -j DNAT --to-destination $SRV1
>
> iptables -A FORWARD -i $EXT_IF -o $INT_IF -p tcp --syn -d $SRV1 \
>   --dport 80 -j ACCEPT

Can we setup server machines behind firewall with same machine ?
Because there is only one machine allow to setup firewall + Internet
Server...

Edward.

Re: Server machines behind Firewall

[Jose Maria Lopez]

El mié, 05 de 01 de 2005 a las 17:14, edwardspl@ita.org.mo escribió:
> Dear All,
> 
> Is there a sample ( nat scripts ) for the title ?
> 
> Edward.

You need to do DNAT from the ports you have in the firewall
to the servers in your internal network.

-- 
Jose Maria Lopez Hernandez
Director Tecnico de bgSEC
jkerouac@bgsec.com
bgSEC Seguridad y Consultoria de Sistemas Informaticos
http://www.bgsec.com
ESPAÑA

The only people for me are the mad ones -- the ones who are mad to live,
mad to talk, mad to be saved, desirous of everything at the same time,
the ones who never yawn or say a commonplace thing, but burn, burn, burn
like fabulous yellow Roman candles.
                -- Jack Kerouac, "On the Road"