Local SMTP Forwarding

Hi All,

I have a IPTables, NAT gateway, and I want to stop local traffic, except
the mail server, from being able to connect to SMTP outside our network.

For instance, some boob with an infected laptop plugged into our network
and we ended up on the spamhuas list for having infected email going out.

Local network is 192.168.99.0/24 on eth0

Anyone know the iptables command I need to do this?

--
Scott
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Re: Local SMTP Forwarding

Never mind, I jumped the gun, I got it, just not in the right place. ;)


Scott Taylor said:
>
> Hi All,
>
> I have a IPTables, NAT gateway, and I want to stop local traffic, except
> the mail server, from being able to connect to SMTP outside our network.
>
> For instance, some boob with an infected laptop plugged into our network
> and we ended up on the spamhuas list for having infected email going out.
>
> Local network is 192.168.99.0/24 on eth0
>
> Anyone know the iptables command I need to do this?
>
> --
> Scott
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>


--
Scott
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Re: Local SMTP Forwarding

iptables -A FORWARD -i eth0 -s ! 1.2.3.4 -o eth1 -p tcp --dport 25 -j DROP
where:
eth0: your internal interface
eth1: your external interface
1.2.3.4: your mail server





>Hi All,
>
>I have a IPTables, NAT gateway, and I want to stop local traffic, except
>the mail server, from being able to connect to SMTP outside our network.
>
>For instance, some boob with an infected laptop plugged into our network
>and we ended up on the spamhuas list for having infected email going out.
>
>Local network is 192.168.99.0/24 on eth0
>
>Anyone know the iptables command I need to do this?
>
>--
>Scott
>-
>To unsubscribe from this list: send the line "unsubscribe linux-admin" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html

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