OLSR mesh with loop potential... having problems.

[John Clark]

I've not had to look in to OLSRD and 'mesh' problems for quite some time.

However, I have a new project and am having problems.

The version of OLSRD i'm using was one that is part of the Debian package set, and has the following version number:

0.5.6-rc7

I downloaded the most recent src from www.olsr.org, and there seems to be some differences in the config file, and it was not able to find the
plugins properly.

In any case, on looking for others who have had problems with olsr and looping, it seems this has been a problem for some time. I don't know why
I didn't see this before when I was using it more, but perhaps most of my 'meshes' were in fact, rather linear or trees and did not contain loops.

Does anyone have some suggestions about dealing with mesh configurations that have potential loops?

Thanks,
John Clark.

[Hans-Christoph Steiner]

I think you should try using a newer version of the package, you can
download pre-built ones here, which should also work for Debian:

https://launchpad.net/~guardianproject/+archive/commotion

I'll also look into putting a newer version of the olsrd package in
Squeeze/backports.

.hc

Post by John Clark
I've not had to look in to OLSRD and 'mesh' problems for quite some time.
However, I have a new project and am having problems.
0.5.6-rc7
I downloaded the most recent src from www.olsr.org, and there seems to be some differences in the config file, and it was not able to find the
plugins properly.
In any case, on looking for others who have had problems with olsr and looping, it seems this has been a problem for some time. I don't know why
I didn't see this before when I was using it more, but perhaps most of my 'meshes' were in fact, rather linear or trees and did not contain loops.
Does anyone have some suggestions about dealing with mesh configurations that have potential loops?
Thanks,
John Clark.

[Henning Rogge]

Post by John Clark
I've not had to look in to OLSRD and 'mesh' problems for quite some time.
However, I have a new project and am having problems.
The version of OLSRD i'm using was one that is part of the Debian
0.5.6-rc7

0.5.6-rc7 is a horrible (and horrible old) version of OLSRd. I would
suggest moving to 0.6.2 or 0.6.3 as soon as possible, otherwise you will
have to deal with a LOT of bugs which have been fixed for years.

Post by John Clark
I downloaded the most recent src from www.olsr.org, and there seems
to be some differences in the config file, and it was not able to
find the plugins properly.

Can you maybe describe what kind of plugins are you using and how your
configuration file looks (and whats the output of olsrd is when you
start with your old configuration file)?

Post by John Clark
In any case, on looking for others who have had problems with olsr
and looping, it seems this has been a problem for some time. I don't
know why I didn't see this before when I was using it more, but
perhaps most of my 'meshes' were in fact, rather linear or trees and
did not contain loops.
Does anyone have some suggestions about dealing with mesh
configurations that have potential loops?

I would suggest you post your configuration file and we have a look over it.

Henning Rogge

[John Clark]

Thanks all,

I updated my olsrd to the 6.3 version that's on the download page. Compiled ok, and did an install and 'install_libs', which seems to have cured my problem with loading the plugins.

I used the default installed olsrd.conf, and only changed the interfaces list.

My net/mesh has 4 nodes, and looks like a 'wheel', where the nodes have direct connection to a 'central node', for 3 direct connections, and there are 2 other connections that connect the 3 other 'outer' nodes.

When I have all the network connections made, the route tables seem to 'work'...

From the point of view of one of the outher nodes, call it Outer-1, when all is connected, I 'see' the Central-Node in the route table as would be expected.

And networks on the Central-Node, that are not directly connected to Outer-1, are listed as 2 hops away.

I also see Outer-2, directly connected to Outer-1 in the 'LINKS' section.

When I unplug (simulating nework outage...) the direct connect between Outer-1 and Central-Node, Outer-1 route tables do not update to forward to Central-Node, via Outer-2.

I'll try to give a text diagram...

Outer-1 <--Link 4-----> Outer-2 <----Link 5---> Outer-3
| | |
Link 1 Link 2 Link 3
| | |
| | |
[ Central-node three separate interfaces connect to the 3 outer node units ]

I'm prototyping this configuration as copper ethernet links... however when this put into the field, all these connections will be radios and attendant potential outage issues.

I consider the links 1-3 'primary'... and the links 4-5 to be 'secondary'...

If someone could 'intuit' what I'm trying to achieve, and either make suggestions on how to do that... or olsrd is not the right routing tool to use for dynamic rerouting like this,
I'd appreciate it...

As a note, in the past, upon reflection, my 'meshes' have been either linear chains or trees, and there have bee no internal loops. I'd hate to have to put in some sort of 'sensing code' to sense the connectivity on the various routes, and bring interfaces up, or shut them down, to force the mesh to be a tree or chain...

Thanks,
John Clark.


When everything is connected, the '2 hop' diagnostic indicates that there 2 networks

Post by John Clark
I've not had to look in to OLSRD and 'mesh' problems for quite some time.
However, I have a new project and am having problems.
The version of OLSRD i'm using was one that is part of the Debian
0.5.6-rc7

0.5.6-rc7 is a horrible (and horrible old) version of OLSRd. I would
suggest moving to 0.6.2 or 0.6.3 as soon as possible, otherwise you will
have to deal with a LOT of bugs which have been fixed for years.

Post by John Clark
I downloaded the most recent src from www.olsr.org, and there seems
to be some differences in the config file, and it was not able to
find the plugins properly.

Can you maybe describe what kind of plugins are you using and how your configuration file looks (and whats the output of olsrd is when you start with your old configuration file)?

Post by John Clark
In any case, on looking for others who have had problems with olsr
and looping, it seems this has been a problem for some time. I don't
know why I didn't see this before when I was using it more, but
perhaps most of my 'meshes' were in fact, rather linear or trees and
did not contain loops.
Does anyone have some suggestions about dealing with mesh
configurations that have potential loops?

I would suggest you post your configuration file and we have a look over it.
Henning Rogge
--
Diplom-Informatiker Henning Rogge , Fraunhofer-Institut für
Kommunikation, Informationsverarbeitung und Ergonomie FKIE
Kommunikationssysteme (KOM)
Neuenahrer Straße 20, 53343 Wachtberg, Germany
Telefon [phone], Fax [phone]
GPG: E1C6 0914 490B 3909 D944 F80D 4487 C67C 55EC CFE0
--
Olsr-users mailing list
https://lists.olsr.org/mailman/listinfo/olsr-users

[Markus Kittenberger]

Post by John Clark
Thanks all,
I updated my olsrd to the 6.3 version that's on the download page.
Compiled ok, and did an install and 'install_libs', which seems to have
cured my problem with loading the plugins.

(you could have done an install_all)

Post by John Clark
I used the default installed olsrd.conf, and only changed the interfaces list.

try to use a new olsrd.conf (i.e an absolutely empty one except the protcol
version ipv4 or ipv6 and the interface names)

this will use default settings for everything, and might cure your actual
problems,..

As a note, in the past, upon reflection, my 'meshes' have been either

Post by John Clark
linear chains or trees, and there have bee no internal loops.

olsrd works on such topologies, as infact such topologies are what it is
meant to operate on.
(it definetely does not need the networks to be a tree,..)

Post by John Clark
I'd hate to have to put in some sort of 'sensing code' to sense the
connectivity on the various routes, and bring interfaces up, or shut them
down, to force the mesh to be a tree or chain...

no need for that,..

Markus

[John Clark]

Post by John Clark
Thanks all,
I updated my olsrd to the 6.3 version that's on the download page. Compiled ok, and did an install and 'install_libs', which seems to have cured my problem with loading the plugins.
(you could have done an install_all)
I used the default installed olsrd.conf, and only changed the interfaces list.
try to use a new olsrd.conf (i.e an absolutely empty one except the protcol version ipv4 or ipv6 and the interface names)

I believe I'm using that conf, all I changed was the interface list.

I'll recheck that...

Post by John Clark
this will use default settings for everything, and might cure your actual problems,..
As a note, in the past, upon reflection, my 'meshes' have been either linear chains or trees, and there have bee no internal loops.
olsrd works on such topologies, as infact such topologies are what it is meant to operate on.
(it definetely does not need the networks to be a tree,..)

I've been working on this more, and will try to give more details as they come to me, but at the moment, I have the problem when the one link is removed, problems arise.


Thanks,
John Clark.

[Érico Porto]

I think he meant a file containing the following lines

IpVersion 4
Interface "wlan0"
{
}

Érico V. Porto

Post by Markus Kittenberger

Post by John Clark
Thanks all,
I updated my olsrd to the 6.3 version that's on the download page.
Compiled ok, and did an install and 'install_libs', which seems to have
cured my problem with loading the plugins.

(you could have done an install_all)

Post by John Clark
I used the default installed olsrd.conf, and only changed the interfaces list.

try to use a new olsrd.conf (i.e an absolutely empty one except the
protcol version ipv4 or ipv6 and the interface names)
I believe I'm using that conf, all I changed was the interface list.
I'll recheck that...
this will use default settings for everything, and might cure your actual problems,..
As a note, in the past, upon reflection, my 'meshes' have been either

Post by John Clark
linear chains or trees, and there have bee no internal loops.

olsrd works on such topologies, as infact such topologies are what it is
meant to operate on.
(it definetely does not need the networks to be a tree,..)
I've been working on this more, and will try to give more details as they
come to me, but at the moment, I have the problem when the one link is
removed, problems arise.
Thanks,
John Clark.
--
Olsr-users mailing list
https://lists.olsr.org/mailman/listinfo/olsr-users

[Vigneswaran R]

Dear all,

Recently we also noticed loops in the routes established by OLSRv1, on a
partial mesh topology (with ~20 machines). We are using olsr 0.6.3 with
default configuration file and only Interface line has updated. Not
using any plugins. As of now wired connections and at the deployment
will be using wireless radios.

Due to the loop, the packets sent through one Interface and received on
another. ssh, ping worked fine regardless of that. However, we realized
the loop when 'nmap' erroneously reported a node as down.

One point to note here is, when we conducted the test we used 10.0.0.0/8
subnet for all the nodes, so that we can do random reconnects to
simulate node movements. However, Henning suggested to put different
Interfaces of the same router into different subnets (in his reply on
another thread). So, when we do the tests again we will see whether that
has any impact on loops.

However, whether loop in routes are expected in general, for such
topologies? or by doing some configuration changes can we avoid that?

Thank you.


Regards,
Vignesh

Post by Érico Porto
I think he meant a file containing the following lines
IpVersion 4
Interface "wlan0"
{
}
Érico V. Porto

Post by John Clark
Thanks all,
I updated my olsrd to the 6.3 version that's on the download
page. Compiled ok, and did an install and 'install_libs',
which seems to have cured my problem with loading the plugins.
(you could have done an install_all)
I used the default installed olsrd.conf, and only changed the
interfaces list.
try to use a new olsrd.conf (i.e an absolutely empty one except
the protcol version ipv4 or ipv6 and the interface names)

I believe I'm using that conf, all I changed was the interface list.
I'll recheck that...

Post by John Clark
this will use default settings for everything, and might cure
your actual problems,..
As a note, in the past, upon reflection, my 'meshes' have
been either linear chains or trees, and there have bee no
internal loops.
olsrd works on such topologies, as infact such topologies are
what it is meant to operate on.
(it definetely does not need the networks to be a tree,..)

I've been working on this more, and will try to give more details
as they come to me, but at the moment, I have the problem when the
one link is removed, problems arise.
Thanks,
John Clark.
--
Olsr-users mailing list
https://lists.olsr.org/mailman/listinfo/olsr-users

[Markus Kittenberger]

Post by Vigneswaran R
Dear all,
Recently we also noticed loops in the routes established by OLSRv1, on a
partial mesh topology (with ~20 machines). We are using olsr 0.6.3 with
default configuration file and only Interface line has updated. Not using
any plugins. As of now wired connections and at the deployment will be
using wireless radios.
Due to the loop, the packets sent through one Interface and received on
another.

you mean return packets just took another route as the packets towards?

this is normal, and you need e.g just 4 nodes with all having 2 etx-1.0
links, aligned in a square, to have a 50% chance to get this, and imho
there is nothing wrong about this,..

Markus

Post by Vigneswaran R
ssh, ping worked fine regardless of that. However, we realized the loop
when 'nmap' erroneously reported a node as down.
One point to note here is, when we conducted the test we used 10.0.0.0/8subnet for all the nodes, so that we can do random reconnects to simulate
node movements. However, Henning suggested to put different Interfaces of
the same router into different subnets (in his reply on another thread).
So, when we do the tests again we will see whether that has any impact on
loops.
However, whether loop in routes are expected in general, for such
topologies? or by doing some configuration changes can we avoid that?
Thank you.
Regards,
Vignesh
I think he meant a file containing the following lines
IpVersion 4
Interface "wlan0"
{
}
Érico V. Porto

Post by Markus Kittenberger

Post by John Clark
Thanks all,
I updated my olsrd to the 6.3 version that's on the download page.
Compiled ok, and did an install and 'install_libs', which seems to have
cured my problem with loading the plugins.

(you could have done an install_all)

Post by John Clark
I used the default installed olsrd.conf, and only changed the interfaces list.

try to use a new olsrd.conf (i.e an absolutely empty one except the
protcol version ipv4 or ipv6 and the interface names)
I believe I'm using that conf, all I changed was the interface list.
I'll recheck that...
this will use default settings for everything, and might cure your actual problems,..
As a note, in the past, upon reflection, my 'meshes' have been either

Post by John Clark
linear chains or trees, and there have bee no internal loops.

olsrd works on such topologies, as infact such topologies are what it is
meant to operate on.
(it definetely does not need the networks to be a tree,..)
I've been working on this more, and will try to give more details as
they come to me, but at the moment, I have the problem when the one link is
removed, problems arise.
Thanks,
John Clark.
--
Olsr-users mailing list
https://lists.olsr.org/mailman/listinfo/olsr-users

--
Olsr-users mailing list
https://lists.olsr.org/mailman/listinfo/olsr-users

[Vigneswaran R]

Post by Vigneswaran R
Dear all,
Recently we also noticed loops in the routes established by
OLSRv1, on a partial mesh topology (with ~20 machines). We are
using olsr 0.6.3 with default configuration file and only
Interface line has updated. Not using any plugins. As of now wired
connections and at the deployment will be using wireless radios.
Due to the loop, the packets sent through one Interface and
received on another.
you mean return packets just took another route as the packets towards?

Yes, exactly.

Post by Vigneswaran R
this is normal, and you need e.g just 4 nodes with all having 2
etx-1.0 links, aligned in a square, to have a 50% chance to get this,
and imho there is nothing wrong about this,..

Ok. Thank you for the clarification.


Regards,
Vignesh

Post by Vigneswaran R
Markus
ssh, ping worked fine regardless of that. However, we realized the
loop when 'nmap' erroneously reported a node as down.
One point to note here is, when we conducted the test we used
10.0.0.0/8 <http://10.0.0.0/8> subnet for all the nodes, so that
we can do random reconnects to simulate node movements. However,
Henning suggested to put different Interfaces of the same router
into different subnets (in his reply on another thread). So, when
we do the tests again we will see whether that has any impact on
loops.
However, whether loop in routes are expected in general, for such
topologies? or by doing some configuration changes can we avoid that?
Thank you.
Regards,
Vignesh

Post by Érico Porto
I think he meant a file containing the following lines
IpVersion 4
Interface "wlan0"
{
}
Érico V. Porto

On Tue, Jun 26, 2012 at 8:29 PM, John Clark
Thanks all,
I updated my olsrd to the 6.3 version that's on the
download page. Compiled ok, and did an install and
'install_libs', which seems to have cured my problem
with loading the plugins.
(you could have done an install_all)
I used the default installed olsrd.conf, and only
changed the interfaces list.
try to use a new olsrd.conf (i.e an absolutely empty one
except the protcol version ipv4 or ipv6 and the interface names)

I believe I'm using that conf, all I changed was the
interface list.
I'll recheck that...

this will use default settings for everything, and might
cure your actual problems,..
As a note, in the past, upon reflection, my 'meshes'
have been either linear chains or trees, and there have
bee no internal loops.
olsrd works on such topologies, as infact such topologies
are what it is meant to operate on.
(it definetely does not need the networks to be a tree,..)

I've been working on this more, and will try to give more
details as they come to me, but at the moment, I have the
problem when the one link is removed, problems arise.
Thanks,
John Clark.
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Olsr-users mailing list
https://lists.olsr.org/mailman/listinfo/olsr-users

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