[Olsr-users] Multiple gateway nodes w/ SmartGateway, config recommendations

[Ferry Huberts]

On 28/03/14 16:54, Ben West wrote:
> Teasing this out from a prior thread, I see these new config params for
> SmartGateway just added to olsrd v0.6.6 (along with features apparently
> relevant to multiple gateways):
>
>        gateway: add SmartGatewayUseCount configuration parameter
>        gateway: use SmartGatewayUseCount setting the the gateway lists
>        gateway: add SmartGatewayEgressInterfaces configuration parameter
>        gateway: add SmartGatewayMarkOffset{Egress,Tunnels} configuration
>           parameters
>        gateway: add SmartGatewayPolicyRoutingScript configuration parameter
>        gateway: initialise a set of fixed tunnel names in/for multi-gateway mode
>        gateway: initialise the egress interface names in/for multi-gateway mode
>        gateway: use fixed tunnel names in/for multi-gateway mode
>        gateway: setup and clear table specific default routes in/for
>           multi-gateway mode
>        gateway: setup/cleanup multi-gateway mode during startup/shutdown of olsrd
>        gateway: introduce and use MULTI_GW_MODE define
>        gateway: enable multi-gateway mode
>        kernel_route: olsr_os_inetgw_tunnel_route now needs the table explicitly
>        Merge branch 'multigw'
>        gateway: also adjust the IPv6 gateway list in olsr_update_gateway_entry
>        gateway: the gateway policy script really is a bash script
>        gateway: cleanup the server tunnel later
>        cfgparser: add SmartGatewayAlwaysRemoveServerTunnel configuration
>           parameter
>        gateway: use SmartGatewayAlwaysRemoveServerTunnel configuration parameter
>        gateway: use tnl_(4|6) tunnel names instead of tnl(4|6)_
>        gateway: properly set the egress interface names
>
>
> I do understand that deploying SmartGateway in a mesh with multiple
> gateway nodes, where each gateway performs NAT to a unique public IP,
> will cause open TCP sessions to break for any repeater nodes that switch
> their gateway.  Likewise, I am assuming this breakage still occurs even
> when all gateway nodes share the same public IP, but the gateway nodes
> themselves sit on a NAT'ed LAN in front of their shared public IP.
> These caveats for mutli-gateway are acknowledged.
>
> I writing to inquire if list members have success deploying SmartGateway
> v0.6.6 in multi-gateway mode, and likewise if anyone has found preferred
> param settings for the new entries listed above.
>

On 0.6.6 it will 'not work', since it lacks some dynamic behaviour.
On master as it is now it will also not work, for the same reason.

We _do_ have it working (brilliantly) in our labs, though with part of 
the functionality in a side-daemon. That part needs to be moved into 
olsrd. This is planned but currently a high-priority task is preventing 
me doing that.

So, I will definitely do this before we cut a new release.

It's is quite spectacular seeing multi-sgw working. Our gateways switch 
very fast (immediately) to a new best gateway and running connections 
are not broken.

Most of our nodes have Internet routes through 3G and some also via 
satcom. We switch dynamically between these depending on circumstances.

So we have dynamic switching on the egress side and dynamic switching on 
the mesh side. And it all works.

If you have a bit of patience then you will be able to use it 
out-of-the-box. My best estimate is somewhere in Q2 :-)

Until then I won't post config for it to avoid getting too many 
questions about unfinished work :-)

-- 
Ferry Huberts