NIC.AT NIC.AT Whois servers are used to locate administrative, technical and security contacts for given IP addresses, domain names or other network objects associated with an organisation, e.g. AS numbers. While usually Top Level Domain (TLD) registries run a whois server, there is no generic name for it and it may not even be obvious that the TLD registry's whois server is the right one to ask, since there are TLDs where registration takes place under specialised second level domains (e.g. UK, AT). The Regional Internet Registries (RIR) also provide whois service as part of their coordination task. All this can be solved by central 'master' or 'meta' whois servers, which keep track of all new and changing servers and refer to the DNS registries' or RIRs' whois servers. This document proposes a DNS-based approach which eliminates the need for a central master repository and works down to lower levels in the hierarchy. It is the intent to locate a whois server as close to the target (in terms of hierarchy) as possible, while preserving the opportunity to locate higher level servers for escalation purposes.