Re: Netfilter and Vonage.

[Tomas Edwardsson <tommi@tommi.org>]

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Jason Price wrote:

>Running Gentoo, kernel version 2.4.24 on a Sparc Ultra 10
>
>I have recently purchased Vonage Voice over IP.  In their 'how to make this
>work with a linksys device', they say (basically):
>
>Forward udp ports 53, 69, 5060, 5061, and 10000-20000 to the device.
>
>I interpret this to mean:
>
>iptables -t nat -A PREROUTING -i eth0 -p udp -d $EXTERNAL_IP \
>		--dport 53 -j DNAT --to 192.168.0.5:53
>
>etc for each port.
>
>Unfortunatly, I don't seem to be able to specify a range of ports in the
>iptables syntax.  So, when I get to that large, 10,000 wide range of ports,
>it dies.  After much tinkering, I find that I can do:
>
>for port in {10000..10597}; do
>   iptables -t nat -A PREROUTING -i eth0 -p udp -d $EXTERNAL_IP \
>		--dport $port -j DNAT --to 192.168.0.5:${port}
>done
>
>and it will work.  If I do just 1 port more, iptables fails, and all the
>tables get magically flushed (which isn't a good idea by the by, but we'll
>get there later).
>
>Idealy, I'd like to:
>
>iptables -t nat -A PREROUTING -i eth0 -p udp -d $EXTERNAL_IP \
>		--dport 10000-20000 -j DNAT --to 192.168.0.5:10000-20000
>  
>

I suggest applying the mport patch to netfilter.
http://www.netfilter.org/patch-o-matic/pom-base.html#pom-base-mport

iptables -t nat -A PREROUTING -i eth0 -p udp -D $EXTERNAL_IP \
    --dports 53,69,5060,10000:20000 -j DNAT --to 192.168.0.5

>Thanks;
>--Jason
>  
>
====
Tomas Edwardsson
HP-UX Certified System Administrator
Red Hat Certified Engineer.


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