Static multicast routing and NAT

Hello all,

I need help for the following problem concerning static multicast
routing and NAT.

I have two networks, one named Internal, the other called External. The
first is attached to eth1 of my linux box and the other to eth0.

On the External network there are routers using DVMRP for multicast routing.

With mrouted running on my box, all it's ok, i.e. multicast packets are
routed from machines in the Internal network to machines in the External
network and from Extrenal network to Internal network.

But, in this project, I'm not allowed to use DVMRP in my box, so I have
to find another solution.

I've tried with smcroute : a multicast packet sent from a machine in the
Internal network is routed to the External network. But, the outgoing
packet has an IP source address from the Internal network. This packet
can't be routed by routers using DVMRP.
If the multicast packet is sent from my box with an IP address from the
External network instead, the packet is routed.

I think that if I can do SNAT for the outgoing packet (changing the IP
source address of the packet) the problem will be solved.

The question is : is it possible to do this with iptables ?

Thankes for your help.

JPI

JPI a écrit :
> Hello all,
>
> I need help for the following problem concerning static multicast
> routing and NAT.
>
> I have two networks, one named Internal, the other called External. The
> first is attached to eth1 of my linux box and the other to eth0.
>
> On the External network there are routers using DVMRP for multicast
> routing.
>
> With mrouted running on my box, all it's ok, i.e. multicast packets are
> routed from machines in the Internal network to machines in the External
> network and from Extrenal network to Internal network.
>
> But, in this project, I'm not allowed to use DVMRP in my box, so I have
> to find another solution.
>
> I've tried with smcroute : a multicast packet sent from a machine in the
> Internal network is routed to the External network. But, the outgoing
> packet has an IP source address from the Internal network. This packet
> can't be routed by routers using DVMRP.
> If the multicast packet is sent from my box with an IP address from the
> External network instead, the packet is routed.
>
> I think that if I can do SNAT for the outgoing packet (changing the IP
> source address of the packet) the problem will be solved.
>
> The question is : is it possible to do this with iptables ?
>
> Thankes for your help.
>
> JPI
>
>

Hello,

Is my question a stupid one or is there another newsgroup better adapted
for this kind of problem ?

JPI

On Mar 20, 5:54*am, JPI <jp.iafra...@free.fr> wrote:
> JPI a écrit :
>
>
>
>
>
> > Hello all,
>
> > I need help for the following problem concerning static multicast
> > routing and NAT.
>
> > I have two networks, one named Internal, the other called External. The
> > first is attached to eth1 of my linux box and the other to eth0.
>
> > On the External network there are routers using DVMRP for multicast
> > routing.
>
> > With mrouted running on my box, all it's ok, i.e. multicast packets are
> > routed from machines in the Internal network to machines in the External
> > network and from Extrenal network to Internal network.
>
> > But, in this project, I'm not allowed to use DVMRP in my box, so I have
> > to find another solution.
>
> > I've tried with smcroute : a multicast packet sent from a machine in the
> > Internal network is routed to the External network. But, the outgoing
> > packet has an IP source address from the Internal network. This packet
> > can't be routed by routers using DVMRP.
> > If the multicast packet is sent from my box with an IP address from the
> > External network instead, the packet is routed.
>
> > I think that if I can do SNAT for the outgoing packet (changing the IP
> > source address of the packet) the problem will be solved.
>
> > The question is : is it possible to do this with iptables ?
>
> > Thankes for your help.
>
> > JPI
>
> Hello,
>
> Is my question a stupid one or is there another newsgroup better adapted
> for this kind of problem ?
>
> JPI- Hide quoted text -
>
> - Show quoted text -
_________________________________________








Hang in there , Wolfgang will be along shortly ....


I have lost much time , scanning NewsGroups
for vital Linux tricks ....
In just a few hours of tracking his posts , i have a wealth
of Linux Networking tips .
I copied it to spreadsheet ( i dont use text editors , too
limited )

Now i put it in my 10 AcerAspires , hook up WiFi
WRT54G's and aluminum dishes ....

No more cellular phones .....



..

JPI <(E-Mail Removed)> wrote:
> On the External network there are routers using DVMRP for multicast routing.

> But, in this project, I'm not allowed to use DVMRP in my box, so I have
> to find another solution.

Why the restriction?
Chris

Chris Davies a écrit :
> JPI <(E-Mail Removed)> wrote:
>> On the External network there are routers using DVMRP for multicast routing.
>
>> But, in this project, I'm not allowed to use DVMRP in my box, so I have
>> to find another solution.
>
> Why the restriction?
> Chris

The restriction is because the team responsible for the network
architecture doesn't want my mrouted (acting as a DVMRP router) to
interact with the "officials" DVMRP routers.

Any idea ?

JPI