what does the DNS WG think about recommending usage of in-addr.arpa for router networks in order to facilitate problem diagnostics? Having IN-ADDR.ARPA nameservers should be considered mandatory for all networks with Internet connectivity. Philip gave a very good reason indeed for this: For users and network operators alike, this is a serious problem if we can't at least pin-point the locality of network outages. This goes for network operators and systems managers, even when the latter can/should contact their network operator(s): as a systems manager I want to be able to quickly pinpoint the spot of a network problem, so I can call on my experience as network manager to be able to make a guess on how long it may last. I must add though that I'm not at a complete loss when there is no IN-ADDR.ARPA resolving for a particular router: I can check the RIPE whois server to see whom the network belong too. Still it's a nuisance if there is no IN-ADDR.ARPA resolving. Piet