[Olsr-users] trouble with NAT and smart gateway

Wed Feb 15 02:43:19 CET 2012

Hi Arjun,

Thank you for your reply.

Your setup is almost the same as mine. I will try your setup and see whether it has any problems.

I will keep you updated if I manage to find anything.

Rdgs,
Paul

________________________________
From: Arjun <(spam-protected)>
To: RC Loh <(spam-protected)> 
Cc: "(spam-protected)" <(spam-protected)> 
Sent: Tuesday, 14 February 2012, 22:48
Subject: Re: [Olsr-users] trouble with NAT and smart gateway

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

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.

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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