Issues recognizing in local network

khuongduybui commented 9 years ago

First of all let me admit that my setup is complex and hard to debug. I will try my best to describe.

I have a main router M, a wifi extender E, a basement router B, a Windows server W, a Windows laptop S, and a Linux VM L running on Hyper-V on W. L is connected to a Hyper-V virtual bridge on W; W is connected via Ethernet to E; E is connected wirelessly to M; M is connected via Ethernet to B; and S is connected wirelessly to B. To simplify it, the route is L -virtual-> W -wired-> E -wifi-> M -wired-> B -wifi-> S. B and E are both set to bridge mode, so all devices are in the same /24 subnet managed only by M.

I have this simple server.js file that are executed on both S and L.

var diont = require('diont')({'broadcast': true});

diont.on("serviceAnnounced", function(serviceInfo) {
    console.log("A new service was announced", serviceInfo.service);
    console.log("All known services", diont.getServiceInfos());
});

var service = {
    name: "server",
    port: "80"
};
diont.announceService(service);

If I start the script above on L then on S, S detects L but L doesn't detect S. If I start it on S then on L, nothing happens at all. I checked that no firewalls are blocking anything.

willemmulder commented 9 years ago

I'm not sure what the problem might be, but I do know that routers can have unexpected behaviour in what messages they will forward to the network and what messages they don't.

I just updated diont to support the manual setting of the TTL for Multicast (although you are using broadcast at the monent). Could you try using Multicast with a TTL of e.g. 10 and see how that works?

var diont = require('diont')({
    ttl: 10
});

Also, I've had problems when I put my PC to sleep and multicast wouldn't work properly after waking up. A fresh restart fixes those problems.

khuongduybui commented 9 years ago

I tried that but it didn't help either. What has been driving me nuts is that one can detect the other but not the opposite.

willemmulder commented 9 years ago

I'm afraid I'm out of ideas as well. Yet, it has probably something to do with packet-routing of a switch/hub somewhere. You might want to try a network-sniffer (e.g. WireShark) to see what's happening at the network-level and see if the right packets arrive at the right places...