[Olsr-users] Pinging not working after an hour

[Vigneswaran R]

On 08/26/2011 06:05 AM, John Tobias wrote:
> Hi Guys,
>
> I have this scenario:  My three devices (devA, devB and devC ) are
> running for an hour, they have a static route (Hna4), NAT (iptables -t
> nat -A POSTROUTING -s 192.168.13.0/24 -j MASQUERADE) and connected to
> the Internet. I could ping outside world, they could see each other
> (see the link table) but, pinging each other didn't work. But, when I
> restart all devices, the ping is working again.

In general, when ping doesn't work, I used to debug in the following way,

1. on both the machines, check the routes for the other machine

     ip ro

OLSRd should have added the routes for the other nodes as it found them.

2. check the iptable on both the machines, just in case any of which is 
dropping packets.

     iptables -L -n

I do 'service iptables stop' (ACCEPT all packets) and try.

3. run tcpdump on both the machines and see whether we receive packets 
or not. sometime the other machine may receive the packets but will not 
reply (due to the absence of route etc).

     tcpdump -i wlan0 -vvv -nn icmp or udp port 698

This should show only the ping packets and the OLSR packets. If olsr 
packets can flow, then ping packets should also be able to flow.

BTW, I am not an expert. Let us hope for others' comments too.

Regards,
Vignesh

>
>
> devA: 192.168.13.251
> devB: 192.168.13.232
> devC: 192.168.13.236
>
> Table: Links
> Local IP        Remote IP       Hyst.   LQ      NLQ     Cost
> 192.168.13.251  192.168.13.232  0.00    0.851   1.000   1.175
> 192.168.13.251  192.168.13.236  0.00    0.372   0.525   5.107
>
> Table: Neighbors
> IP address      SYM     MPR     MPRS    Will.   2 Hop Neighbors
> 192.168.13.236  YES     NO      NO      4       1
> 192.168.13.232  YES     YES     NO      4       1
>
> Table: Topology
> Dest. IP        Last hop IP     LQ      NLQ     Cost
> 192.168.13.236  192.168.13.232  0.557   0.541   3.317
> 192.168.13.251  192.168.13.232  1.000   0.851   1.175
> 192.168.13.232  192.168.13.236  0.553   0.514   3.520
> 192.168.13.251  192.168.13.236  0.576   0.372   4.656
> 192.168.13.232  192.168.13.251  0.851   1.000   1.175
> 192.168.13.236  192.168.13.251  0.372   0.525   5.107
>
> Table: HNA
> Destination     Gateway
> 0.0.0.0/0       192.168.13.251
>
> Table: MID
> IP address      Aliases
>
> Table: Routes
> Destination     Gateway IP      Metric  ETX     Interface
> 192.168.13.232/32       192.168.13.232  1       1.175   wlan0
> 192.168.13.236/32       192.168.13.236  1       5.107   wlan0
>
> Any idea?
>
> john
>


-- 
Vigneswaran R
TCS Innovation Labs
Hyderabad
Ph: +91-40-66673582
Ext: 73582
Cell: 9441015617