Re: [B.A.T.M.A.N.] Internet gateway or not: dhcp or static ip?

["Geneviève Bastien" <gbastien@versatic.net>]

Hi Guido,

Thanks for the links.  I guess we have the same general idea, yours is 
more developed than mine.  Can I borrow some of your scripts?

These packages could be made available to the batman community.  I think 
they solve a common scenario and could be useful to others, though I did 
learn a lot about hotplug by working on this problem :D

Cheers,
Geneviève


On 12-07-18 09:35 PM, Guido Iribarren wrote:
> Another stab at this, which solves a slightly different scenario:
>
> https://bitbucket.org/guidoi/batmesh/raw/ee7042b01ebe/packages/batman-adv-auto-gw-mode/files/etc/hotplug.d/net/99-batman-gw
>
> This makes no assumptions about the interface (static or dhcp), but
> instead asks for a lease in an alias (br-lan:ipv4)
>
> this is part of a bigger idea
> https://bitbucket.org/guidoi/batmesh/src/ee7042b01ebe/packages/batman-adv-auto-gw-mode/
>
> in a nutshell: every node is initially set to gw_mode=client, with
> static ip and DHCP server (through dnsmasq) offering leases.
> so if a client connects to the cloud, it gets an ipv4 and has basic
> connectivity with other clients (bat cloud has no internet access)
>
> if one node has internet connection, sets gw_mode=server, (either
> manually or by some magic script) , and this is recognized by other
> nodes by this hotplug.d hook, which requests an ipv4 (so that routers
> can do "opkg update" and sync ntp time) and at the same time kills the
> local dhcp server, so that new clients get the lease from the internet
> gateway dhcp.
>
>
> On Wed, Jul 18, 2012 at 10:18 PM, Geneviève Bastien
> <gbastien@versatic.net> wrote:
>> Hi!
>>
>> I had a chat the other day on IRC about how to assign ip addresses whether
>> there is an internet gateway available or not.
>>
>> Here is the problem and the solution I came up with.  Let me know if that
>> makes sense or if I'm complicating my life.
>>
>> * Problem *
>>
>> Our network is still small, there may or may not be an internet gateway
>> available on it, it doesn't matter.  From what I read here
>> http://www.open-mesh.org/projects/batman-adv/wiki/Gateways for nodes to have
>> access to the internet, the internet gateway has to be a dhcp server.
>>
>> The node requests an ip by dhcp and then knows what the default route is.
>> But if the gateway disappears, there is no more dhcp server, the nodes do
>> not have ip addresses and the mesh network is about useless.
>>
>> But if I set nodes with static ips, then the mesh is routable all the time,
>> but nodes do not know the default route to reach the internet.
>>
>> Am I right so far?
>>
>> * Solution *
>>
>> Someone on irc pointed me out to this page:
>> http://www.open-mesh.org/projects/batman-adv/wiki/Uevent
>> I use this uevent to send a dhcp request if a gateway becomes available or
>> go back to a static ip if all gateways are gone.
>>
>> Attached is the hotplug script I use.  It is in
>> /etc/hotplug.d/net/99-batman-adv-gw.  It supposes the interface is
>> configured by default with a static ip.
>>
>> It works perfectly, but I can't believe there is no simpler solution to
>> this.  Our problem should be a quite common one.  What is the general
>> solution to it?
>>
>> Thanks,
>> Geneviève