[Olsr-users] Strange OLSR behaviour

[Markus Kittenberger]

using the same ip adress on multiple interfaces can lead to strange
problems,..
(the OLSR protocol requires meshwide unique interface adresses)
at the moment there is a warning afair on startup, an in future olsrd will
very probably refuse to start/run on an interface without an unique ip.

do you have 2 links with an identical pair of ip-adresses? (this will lead
to routing catastrophes for sure,.. expecially if the 2 links have different
lq or nlq values)

or one node having the same neighbour twice (on 2 interfaces, where the
neighbour has the same interface) ?

regards Markus

On Sun, Jan 10, 2010 at 11:58 PM, Mitar <(spam-protected)> wrote:

> Hi!
>
> We have connected a new node with directional antenna to one of our
> nodes (which has an omni antenna) and on this node with omni antenna
> VPN uplink currently does not work. Because of this we have discovered
> really strange OLSR behaviour.
>
> The central node is "fri" node (with omni antenna):
>
> https://nodes.wlan-lj.net/nodes/node/fri
>
> and it connects to three nodes "gerbiceva-49", "glinska-9" and
> "stefanova-15-ii". Or better, those three nodes connect to it with
> their directional antennas. "stefanova-15-ii" is this new node which
> has rather flapping link because it uses wrong polarisation. The
> problem is that those two nodes ("glinska-9" and "fri") are cut off as
> the link from "stefanova-15-ii" is flapping. But all this while link
> to "gerbiceva-49" is good: I have SSHed to "fri" node from
> "gerbiceva-49" node and was able to normally work on it. At the same
> time I have let running ping (with default packet size) in both
> directions (between "fri" and "gerbiceva-49" nodes) and in few hours
> there was just 4% of packet loss in both directions without any
> periods of link loss.
>
> But OLSR is adding and removing route to "fri" node all the time so
> from network it is mostly unreachable. (I have to connect to it
> directly from  "gerbiceva-49" node.)
>
> Our current mesh topology can be seen here:
>
> https://nodes.wlan-lj.net/nodes/topology
>
> It is strange that sometimes route is removed and then topology is
> drawn with "glinska-9" and "fri" nodes in the "air" - not connected to
> the rest of the mesh but still drawn. While route between "fri" and
> "gerbiceva-49" is not drawn. And at the same time ping normally works
> between "fri" and "gerbiceva-49".
>
> We use OLSR 0.5.6-r7 on nodes with such configuration:
>
> AllowNoInt yes
> UseHysteresis no
> LinkQualityFishEye 1
> LinkQualityLevel 2
> LinkQualityAging 0.1
> LinkQualityAlgorithm "etx_ff"
> LinkQualityDijkstraLimit 0 9.0
> FIBMetric "flat"
> Pollrate 0.025
> TcRedundancy 2
> MprCoverage 3
> MinTCVTime 500.0
> NatThreshold 0.75
>
> Interface "wl0"
> {
>  Ip4Broadcast 255.255.255.255
>  HelloInterval 5.0
>  HelloValidityTime 40.0
>  TcInterval 2.0
>  TcValidityTime 256.0
>  MidInterval 18.0
>  MidValidityTime 324.0
>  HnaInterval 18.0
>  HnaValidityTime 108.0
> }
>
> And tap0 interface has LinkQualityMult default 0.80 added. And yes, we
> have the same IP addresses on all interfaces (so on "gerbiceva-49"
> both tap0 and wl0 interface has the same address).
>
>
> Mitar
>
> --
> Olsr-users mailing list
> (spam-protected)
> http://lists.olsr.org/mailman/listinfo/olsr-users
>
>
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