[Olsr-users] trouble with NAT and smart gateway

Tue Feb 14 16:54:42 CET 2012

Op 14 feb. 2012, om 15:48 heeft Arjun het volgende geschreven:

> Hi Paul,
> My network setup looks as follows:
> Nodes with interfaces running OLSR (192.168.10.0/24):
> A, B, C
> 
> Nodes with interfaces not running OLSR (192.168.1.0/24):
> C, D
2 nodes with same HNA?

I suggest the following:
Allocate a /24 to each node:
	A: 192.168.1.0/24
	B: 192.168.2.0/24
	C: 192.168.3.0/24
And on MANET interfaces:
	A: 192.168.10.1/24
	B: 192.168.10.2/24
	C: 192.168.10.3/24
Configure interfaces, olsr config etc.
Then check IP connectivity on each link (ping). Check with arp, tcpdump etc.
Probably and hopefully it works on your current gear.

> Gateway, announcing HNA4 status:
> C
> 
> NAT notes:
> C runs NAT to masquerade packets coming from the mesh and going to the non-OLSR 192.168.1.0/24 network.
not again :-((

Teco

> 
> I am planning to get wifi devices with the atheros chipset and install them on all my nodes and see if OLSR works. Markus suggested that things get easier if I use the same wifi devices for all the olsr nodes. 
> regards,
> Arjun.
> 
> 
> On Mon, Feb 13, 2012 at 8:35 PM, RC Loh <(spam-protected)> wrote:
> Hi Arjun,
>  
> Is it possible that you provide a simple network diagram on where is your gateway, node D, node C and node A?
>  
> I am also facing some problems in configuring a gateway for my OLSR mesh.
>  
> Probably, I can get some inputs from your problem.
>  
> Rdgs,
> Paul
>  
> 
> From: Arjun <(spam-protected)>
> To: Vigneswaran R <(spam-protected)> 
> Cc: (spam-protected) 
> Sent: Tuesday, 14 February 2012, 5:50
> Subject: Re: [Olsr-users] trouble with NAT and smart gateway
> 
> Hi Vignesh,
> I need NAT because node D is constrained to talk only to 192.168.1.2. I therefore masquerade the packets coming in from the mesh to translate their source ip addresses to 192.168.1.2. I think my problem is more to do with congestion of the mesh network due to high bandwidth usage by my application which runs on node A.
> Thanks much!
> Arjun.
> 
> 
> On Mon, Feb 13, 2012 at 2:32 AM, Vigneswaran R <(spam-protected)> wrote:
> On Saturday 11 February 2012 03:38 AM, Arjun wrote:
> [...]
> 
>> I have to use the NAT iptables rule on Node C, because Node D (192.168.1.1) can only talk to 192.168.1.2, which is IF2 on Node C. So packets originating from the OLSR mesh must have their source ips masqueraded to 192.168.1.2. Now that I think of it, maybe I can nose around inside the linux box on Node D (which is actually a commercial toy) and see if I can open it up to connect to ip addresses other than 192.168.1.2.
> 
> I think, NAT can be removed from your setup due to the following reason,
> 
> 1. OLSR machines have route to D (and it's network) via C (because of HNA)
> 2. So, the packets originated from OLSR mesh reach C and then forwarded to D.
>   -- Here, C does simple IP Forwarding (no NATting)
>   -- And the forwarded packets will have the source IP unmodified
> 3. Since D doesn't have route to that source IP, it will send the reply packets to/via the default gateway (which is C, I believe).
> 4. When C receives this reply packet, it routes it to the proper destination in the OLSR mesh.
> 
> 
> Regards,
> Vignesh
> 
> 
> 
>> I think the problems I have are most likely due to mobility, because the toy moves reasonably fast, and leaky UDP streams. I will shorten the Hello/TC intervals and see if that helps. Do let me know if any other suggestion comes to mind.
>> Thanks again!
>> Arjun.
>> 
>> 
>> On Fri, Feb 10, 2012 at 2:46 PM, Markus Kittenberger <(spam-protected)> wrote:
>> afair smart-gateway does not do anything useful for your setup,.
>> as its only for hna announcements of 0.0.0.0/0 (and useful only if u have multiple nodes announcing this)
>> 
>> anyways to simplify things, do not use smartgateway, hna alone is enough!
>> 
>> and if possible (to simplify more) also remove the NAT in your testcase, use a static route on your target towards the mesh inestead,..
>> 
>> or just try (and verify the amount of packetloss of) an udp stream to node C, and not the node behind C,.. (so you can leave away the hna too)
>> 
>> if this simplified setup works, you have issues with nat/hna,..
>> if not, you have problems with mobility (which usually can causes "some" packetloss, and maybe just too much for your udp stream)
>> 
>> On Fri, Feb 10, 2012 at 7:07 PM, Arjun <(spam-protected)> wrote:
>> However, when I move node B out of range from the gw, i.e. node C, so that it is 2 hops away, which I confirmed from debug output from the txtinfo plugin, it is not able maintain connectivity (tcp and udp streams) with node D
>> and is it able to maintain conenctivtiy with C?
>> or atleast with A? 
>> and my application on node B breaks down. Are there any settings I am forgetting,
>> if (and only if) u are moving out of range fast, u might need shorter hello/tc intervals,..
>> or is it that UDP data over OLSR is not a good idea.
>> as long as u do not expect no packetloss, udp works fine,.. 
>> 
>> 
>> Markus
>> 
>> 
>> 
>> 
> 
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