Hi, While the discussion of DNS configuration is nice, I can we steer back to the underlying cause: 1. Old versions of the Xrootd client are known to log in to a server via IPv6 but set `dual-stack:false` despite the worker node actually being dual-stack. This has already been fixed in newer Xrootd versions. * It is not an option to remove the old versions of the client from use until about 2019-or-so. 2. Current server versions adhere to protocol spec and trust the client's setting of the dual-stack flag. 3. We would like the ability to break the protocol spec and have the server always treat things as if IPv6 client's dual-stack flag was always set to true. As far as I can tell, neither DNS configuration nor server version comes into play here. Brian -- You are receiving this because you commented. Reply to this email directly or view it on GitHub: https://github.com/xrootd/xrootd/issues/411#issuecomment-245978742 ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-DEV list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-DEV&A=1