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

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

[Geneviève Bastien]

[-- Attachment #1: Type: text/plain, Size: 1538 bytes --]

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

[-- Attachment #2: 99-batman-adv-gw --]
[-- Type: text/plain, Size: 729 bytes --]

#!/bin/sh

# This is the interface as mentioned in the /etc/config/network file
IMESH="lan"

# This is the interface on which to ask for dhcp.  May not be same as previous if interface is a bridge, like br-lan
IDHCP="br-lan"

hostname=$(uci get system.@system[0].hostname)

case "$ACTION" in
	change)
		if [ "$BATTYPE" == "gw" ]; then
			case "$BATACTION" in
				add)
					logger "Now has a gateway available.  Will request dhcp."
					udhcpc -i $IDHCP -h $hostname
					;;
				del)
					logger "No more gateway available.  Will go back to static ip."
					ifdown $IMESH
					ifup $IMESH
					;;
				change)
					logger "New default gateway.  Will request dhcp"
					udhcpc -i $IDHCP -h $hostname
					;;
			esac
		fi
		;;
esac

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

[HeXiLeD]

Have you tried to set every node with static ip but also providing dhcp 
server to a range of ips ?
For example: node 1 from 192.168.1.1 to 192.168.1.10 then node 2: 
192.168.1.11 to 192.168.1.20 and so on.

On 07/18/2012 09:18 PM, Geneviève Bastien 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

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

[Guido Iribarren]

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

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

[Geneviève Bastien]

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

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

[Guido Iribarren]

Please do! Reuse it, modify it, adapt it,
i didn't think they were enough lines of code to reserve a gpl notice :)

the intention is indeed to make this available, upstream in openwrt
official packages, but i'm still getting the grip on sending patches
and stuff
in the meantime any feedback is much appreciated

On 7/19/12, Geneviève Bastien <gbastien@versatic.net> wrote:
> 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
>
>
>