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In my work network UDP broadcast networks are isolated between the WiFi and wired channels, so LAN sync discovery does not work. Is there a way to explicitly tell Dropbox to try a specific IP address for LAN sync?

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Are you sure it's just broadcast UDP being dropped? Are the wired hosts on the same IP network as the wifi hosts? (same prefix and netmask?) How about ICMP broadcasts? ie: ping Is ARP working? – Nevin Williams May 11 '13 at 0:23
No, the netmask is different as well. We have several 10.x.x.x subnets with VLANs there, and direct communication is allowed. This is by design. I have switched jobs since, though, so this question is no longer relevant to me. :) – Ekevoo Jul 25 '13 at 23:03
Well, UDP broadcasts are usually only directed at hosts on the same network/netmask. While they might be sent to all hosts, a host won't respond to broadcasts that aren't on the same network either. That's essentially the purpose of network/netmask pairs: to partition broadcast domains. – Nevin Williams Jul 26 '13 at 0:40
I know that's the point of UDP broadcasts, however, Dropbox LAN sync makes an assumption that only hosts in the same subnet are good. This is a very good assumption, but in that case, it didn't apply to me. – Ekevoo Jul 26 '13 at 2:25
I don't know if the software was responsible; this would be at the kernel level... – Nevin Williams Jul 26 '13 at 3:16

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