[Olsr-users] INFINITE cost in all links

Antonio Anselmi (spam-protected)
Fri Jul 25 12:11:33 CEST 2014

Hi all,
I'm facing an odd problem that recurs randomly, without any user
intervention, at different times on a single-gateway network.
Suddenly, all the links of the gateway node have their NLQ values equal to
zero and the respective LQ values greather than zero, so every link has an
INFINITE cost -> olsrd route table is empty -> ip main route table is empty.
Just because all NLQ values are zero, it seems that the nodes do not
receive/hear olsrd packets from the gateway, but , at the same time, the
gateway itself continues to receive and process packets sent by the other
node (LQ values change in time).

In this situation, I logged to the gateway node and run the command
'tcpdump -vv -ni wlan0-1 port 698' (wlan0-1 is the adhoc interface) to
inspect the way olsrd was working.
As supposed:
1) the gateway had stopped transmitting olsrd packets but continued to
receive and process olsrd packets sent by the other nodes
2) olsrd route table and ip main route table were empty and the gateway
does not ping any other node
3) the topology seen by the gateway have no node reachable
4) at layer2 the neighbors are all associated (iw dev wlan0-1 station dump)
so adHoc beacons travel
Stopping and restarting olsrd does not fix the stalemate as well as
manually populating the ip main route table. Obviuosly, rebooting the node
all goes right ...untill the next olsrd stale.

I'm wondering:
1) Why all links go to INFINITE cost? (A loop caused by LQ mechanism?)
2) may be the case that the gateway try to transmit olsrd packets, but
since its route table is empty, no packet reach the adHoc interface
(loop inside the gteway) ?
3) since the TC-LQ packets sent by the nodes (and received by the gateway)
do not show the gateway (NLQ = 0) why these packets reach the gateway?
Nodes should have no route to the gateway since they do not hear it!
4) and... the all_INFINITE_costs situation (as well as the empty routing
tables) is a "cause" or an "effect" ?

Have you some directions?


For your information:
- network is 17 nodes + 1 gateway node, every node has an AP for wireless
user connections
- openwrt trunk r37737, kernel 3.10.4
- ath9k from kmod-mac80211 3.10.4+2013-06-27-1
- olsrd.conf file below

DebugLevel 0
IpVersion 4
AllowNoInt yes
Pollrate 0.05
TcRedundancy 2
MprCoverage 7
LinkQualityFishEye 1
LinkQualityLevel 2
UseHysteresis no
NatThreshold 0.5

Interface "wlan0-1"
    HelloInterval 6.0
    HelloValidityTime 108.0
    TcInterval 4.0
    TcValidityTime 324.0
    MidInterval 18.0
    MidValidityTime 324.0
    HnaInterval 18.0
    HnaValidityTime 108.0

LoadPlugin "olsrd_txtinfo.so.0.1"
    PlParam "port" "8090"
    PlParam "Host" ""

LoadPlugin "olsrd_dot_draw.so.0.3"
   PlParam "port" "2004"

LoadPlugin "olsrd_httpinfo.so.0.1"
    PlParam     "port" "8080"
    PlParam     "Net" ""

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