The problem *does* occur with non-broken DNS servers, too. I just tried the test program "test3.c" attached to my comment from 2007-05-13 on a system booted from a Lucid alpha3 live CD, and it still takes more than five seconds to execute. The system was directly querying a BIND 9 DNS server, and there was no "cheap home router" involved. This is trivial to reproduce; please try it.
Why is Ubuntu doing mDNS lookups for reverse mappings, anyway? I can see the utility of doing mDNS for forward mappings, but doing mDNS for reverse mappings seems not only harmful (being the cause of this bug), but also quite pointless.
The problem *does* occur with non-broken DNS servers, too. I just tried the test program "test3.c" attached to my comment from 2007-05-13 on a system booted from a Lucid alpha3 live CD, and it still takes more than five seconds to execute. The system was directly querying a BIND 9 DNS server, and there was no "cheap home router" involved. This is trivial to reproduce; please try it.
Why is Ubuntu doing mDNS lookups for reverse mappings, anyway? I can see the utility of doing mDNS for forward mappings, but doing mDNS for reverse mappings seems not only harmful (being the cause of this bug), but also quite pointless.