[Olsr-users] trouble with NAT and smart gateway

[RC Loh]

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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