Comment 142 for bug 417757

This is as Jeroen and others have pointed out repeatedly, primarily an issue with broken resolvers/forwarders often part of cheap broadband/wlan routers. I just want to repeat that this isn't specific to IPv6, and emphasise that changes in karmic have made things worse.

Karmic always first tries to append the local/search-domain to requests. That is an important change from previous versions where search-domains are appended only when the client application only specifies the host-part.

In the last couple weeks I've come across number of different broadband CPE's (multiple brands) which have a DNS-forwarder that fails to forward nxdomain responses to the clients. In the past these clients would only experience delays for non-existent hosts. After upgrading to karmic they get a 20sec delay for every request. I.e. the user types "ubuntu.com" in the browser, karmic first tries "ubuntu.com.searchdomain" and sits waiting as the nxdomain-response is lost.