LCM UDP Message Through Shared Network

Question

Folks,

I have a Ubuntu machine connected to the Internet through wireless (wlan0), and I am sharing this connection to my Ethernet port (eth1). Then, I have this Ethernet port connected to a switch, and two windows machine connected to the same switch. So the two windows machines have a static IP from the LAN generated from the route generated from wlan0 to eth1, so that I can communicate with all 3 computers at the same time (this works since I can ssh and remote access all 3 computers).

My problem is that I when I run my LCM program (with TTL = 1) on my windows PC, I cannot receive the messages on my Ubuntu machine (meaning that the message should pass through the Ethernet). How can I make sure the UDP messages can be routed back into my Ubuntu machine from the windows machines while the wireless network is running?

A router (your Linux machine is routing) will drop a packet with a TTL of 1. It receives the packet, decrements the TTL, which becomes 0, then drops it because the TTL is expired. — Ron Maupin, Mar 01 '17 at 23:20

score 0 · Accepted Answer · answered Mar 02 '17 at 19:22

0

This was my solution to the problem (right there on the LCM website):

sudo ifconfig eth1 multicast
sudo route add -net 224.0.0.0 netmask 240.0.0.0 dev eth1

Now all my UDP packets are routed only through eth1. And my shared network (from wlan0) is still intact after this. So all computers have internet at the same time. So great!

answered Mar 02 '17 at 19:22

Pototo

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my question is now, how do I make this a persistent change without having to enter my password every time I restart my Linux computer? – Pototo Mar 02 '17 at 19:23
Perhaps you should ask your questions on the correct SE site, like [ubuntu.se] or [unix.se] – Ron Maupin Mar 02 '17 at 19:35
Aight...will do that – Pototo Mar 10 '17 at 18:38

LCM UDP Message Through Shared Network

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