[Olsr-users] Pinging not working after an hour
Fri Aug 26 07:06:01 CEST 2011
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
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
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.
> 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?
TCS Innovation Labs
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