I have an issue on my network that I cannot explain. Somehow, wifi clients connected to the network cannot access some wired resources on the same network while they can access others. The wifi client and the wired resource are both on the “trusted” network, which uses the default VLAN. The wifi clients get IPs in the same range as the wired resources that they cannot connect to.
On the trusted LAN network I have a wired printer and a wired Synology NAS. With my iPhone, when connected to the trusted Wifi, I can use the printer. But I cannot approach the NAS. Not through a dedicated app (DS File) and not through the browser. Nothing happens. There’s no evidence any traffic from the iPhone ever arrives at the NAS. After a while, the connection attempt times out. But printing from the iPhone works…
The firewall on the NAS is disabled. The logs on the NAS show no evidence of something trying to get in.
The firewall on the Balance One is enabled. But, I would not expect this traffic to be subject to the firewall: all traffic is on the same network. The Default rule is any to any allowed. Just for fun I configured a “trusted network to trusted network” firewall rule, all traffic allowed and logged. But nothing shows in the logs.
The wifi has no client isolation, at least, not configured through the GUI. “Block all private IP” is not ticked.
What am I missing? What could be causing this? Since I do not see anything happen on the NAS I suspect that the router must be blocking the traffic, or misrouting it. But why? And how to debug this?
I downloaded a network tools app on the iPhone. I can ping google.com allright but cannot ping any internal resource, not the printer and not even the router itself.