The name servers for the domain elby.ch do not reverse resolve. For example: ns1.elbyns.de resolves to 62.116.130.76, but 62.116.130.76 does not resolve back ns1.elbyns.de. It's not clear through the RIPE Whois search (this IP block is within a RIPE range) who does name service for the IP block. Contact your local provider to arrange for the IP to reverse resolve properly. K -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu]On Behalf Of Geo. Sent: Monday, October 20, 2003 8:56 AM To: nanog@merit.edu Subject: Need a DNS expert Got something really weird going on and I need a bit of help from someone who is really good with dns. Domain elby.ch seems to resolve from some DNS servers but not from others. Can you see anything that might break dns resolution for this domain? Specifically it appears NT4 dns servers with SecureResponses turned on. Please feel free to answer me offlist. Geo.