Ping not working between two devices when going trough a switch with nothing else connected

Question

(Apologies in advance if this is misplaced here. I'm trying to integrate a NAS into my network and have multiple problems. This is one of several questions that I'm planning to ask about this here.)

I've got a network problem, and my thinking is, first check whether ping works.

When I'm connecting a Synology NAS to a Mac (10.6.8) directly through an ethernet cable, everything works fine, including pinging the NAS from the Mac. I gave the NAS the name "sini", and on the mac

ping sini.local

works fine (I receive back packets).

Now once I do just a very small change - connecting the two devices through a switch (netgear GS108), which has nothing connected except these two devices - and now when I do

ping sini.local

just gives me "request timeouts".

Questions:

• first check that ping works, is that the right way to go about debugging a network?

• Does zero configuration networking not work through switches? What am I doing wrong?

• Funny thing is, the main NAS functionality (through afp) works in both cases. It's just ping and the web interface access that is not working in the second case. Why?

Thanks for any help!

Answer 1

first check that ping works, is that the right way to go about debugging a network?

This is one way to go about troubleshooting a network. In my personal experience I've always reached effective results following the OSI layers, starting at the Physical layer. In other words, check cabling, connectors and equipment. Following that I start checking local connectivity to network interfaces and from there trying to reach other nodes and so forth.

Does zero configuration networking not work through switches? What am I doing wrong?

zerconf should not be affected when going through a switch. This is a usual scenario for most zeroconf devices. If however the switch is managed and configured, the configuration may intervene normal behaviour. Your switch, GS108, is not managed and should not effect the behavior of zeroconf.

I suggest doing a arp -a in cmd. Initiate ping to the DNS record(sini) of your NAS and then check the ARP table again to verify if you see a new entry and if so from what IP. This would verify if your DNS resolution works and also provide you with the IP of your nas which you can use to connect through directly.

Try switching network It might be your DNS that is not working correctly.

Answer 2

It is possible bonjour (mDNS zeroconfig) is not working through the router. It uses multicast which sometimes gets blocked by routers. Most often it will work when both devices are physically on the same switch chip, but lan to wlan often doesn't work and lan to wan almost never works (and in most cases it shouldn't). If you can figure out the actual IP address for the synology, you could ping that instead.

Edit: timeout indicates the mDNS name was resolved but ICMP is not... Should have noticed that earlier.