any vpn software or third-party firewalls on the mac? Anything else strange about the mac?
What you describe doesn’t seem possible. If you aren’t seeing it from itunes or bonjour browser, it can only be a few things —
the mdns responder isnt’ running on your mac.
you are firewalled, or some other networking issue is blocking multicast
That’s really it… I can’t think of anything it might be other than a fundamental networking thing.
No VPN / No third-party firewall / The MDNS responder is running (it correctly returns Bonjour services available locally, like SSH).
Now, I think the issue occurs because the Mac also serves a gateway to Internet (through ipfw ant natd) for the others computers on the network. However, when I disconnect from internet and remove all ipfw rules (so no more NAT), this does’nt fix the thing. Also, I observed that 126.96.36.199 (the multicast address used by Bonjour) was routed to ppp0. However, manually shutting down this interface and even adding a specific route to en0 didn’t fix the problem…
So yes, I think this is linked in some way to the network config, but I really do not see how to fix this… 🙁