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<div class="moz-cite-prefix">On 10/31/2014 11:19 AM, akshay
mithyantha wrote:<br>
</div>
<blockquote
cite="mid:CA+ZzFK1TPWOF3MkDdDHQ_EoniP13BH66FtM=J3CqByNY58k4WA@mail.gmail.com"
type="cite">
<div dir="ltr"><font style="background-color:rgb(255,255,255)"
color="#000000" face="courier new, monospace"><span class="im"
style="font-size:13px"><font color="#000000">Hello,
<div><br>
</div>
<div>A project I've been working on requires data to be
sent on multihop network.</div>
<div><br>
</div>
<div>I've used 3 DELL laptops which has Broadcom BCM4365
wireless hybrid adapter and a Linksys WRT 54GL router.
The devices are running OLSR 0.6.7. As the loss was very
high when the devices were kept afar, I've put the
devices in the same room.</div>
<div><br>
</div>
<div>Consider device A, B, C to be the laptops and device
D to be the router.</div>
<div>Currently all devices can communicate with each
other.</div>
<div><br>
</div>
</font></span><span class="im" style="font-size:13px">
<div><font color="#000000">Now as I wanted the devices to
communicate only to its immediate neighbor, I manually
blocked the 2nd hop and 3rd hop neighbors using the
following command.</font></div>
<div><span style="color:rgb(0,0,0)"> sudo iptables -A
INPUT -m mac --mac-source <mac id> -j DROP</span></div>
<div><font color="#000000"><br>
</font></div>
<div><font color="#000000">The device A can send data only
to B blocking C and D, B can send data to A and C but
blocked D, C can send data to B and D, but blocked A and
D can send data to C but blocked A and B.</font></div>
<div><font color="#000000"><br>
</font></div>
<div><font color="#000000">The topology being </font></div>
<div><font color="#000000"> A <-----> B
<-----> C <-----> D</font></div>
<div><font color="#000000"><br>
</font></div>
<div><font color="#000000">An example of the current routing
table of A after manually blocking of other neighbors is</font></div>
<div><font color="#000000"> 1st hop 2nd hop</font></div>
<div><font color="#000000"> B C</font></div>
<div><br>
</div>
</span></font>
<div style="font-size:13px"><font
style="background-color:rgb(255,255,255)" color="#000000"
face="courier new, monospace">The device A can ping its 2nd
hop neighbor device C through B.</font></div>
<div style="font-size:13px"><span
style="color:rgb(0,0,0);font-family:'courier new',monospace"><br>
</span></div>
<div style="font-size:13px"><span
style="color:rgb(0,0,0);font-family:'courier new',monospace">But
the device B cannot ping its 2nd hop neighbor router D.</span><font
color="#000000" face="courier new, monospace"><img
moz-do-not-send="true" class=""
src="https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif"></font></div>
<div class="" style="font-size:13px"><span class="im"
style="background-color:rgb(255,255,255)"><font
color="#000000" face="courier new, monospace">
<div>The device A cannot pass data to 3rd hop neighbor
router D.</div>
<div>The router can ping only its immediate neighbor C.</div>
<div><br>
</div>
<div>Is this problem due to incompatibility of network
adapters of laptop and the router? Should I replace the
laptops with the routers or is there any other issue
that I don't know of?<br>
</div>
</font></span></div>
</div>
</blockquote>
<br>
To ensure that your network configuration is correct, do the
following:-<br>
<br>
On A:<br>
1. manually add route to C via B<br>
2. manually add route to D via B<br>
<br>
On B:<br>
<br>
1. enable ip_forward<br>
2. manually add route to D via C<br>
<br>
On C:<br>
<br>
1. enable ip_forward<br>
2. manually add route to A via B<br>
<br>
On D:<br>
1. manually add route to A via C<br>
2. manually add route to B via C<br>
<br>
Now, you should be able to ping end to end (A ==> D, D ==> A).<br>
<br>
If that happens, there is no problem with your network adapters and
configuration.<br>
<br>
Regards,<br>
Vignesh<br>
<br>
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