I have a java client program that uses mdns with service discovery to find its associated server. After much testing on a single network with Windows, Fedora 10, and Ubuntu 8.10, we delivered a test build to a customer. They report that the client and server never connect. They sent us a wireshark capture that shows the mdns packets have a TTL of 1 even though our code sets it to 32. When we test locally, the TTL is 32 just like we set it. The customer is using Redhat Enterprise 5.
I saw Java Multicast Time To Live is always 0 but it leaves me curious as to why that question asker has a TTL of 0, but mine is 1.