smb@ulysses.att.com (Steven Bellovin) (10/09/90)
I just retrieved an RFC defining some new RR types for the DNS. A few things bother me. First, it isn't clear to me that X25 address and ISDN address should be separate types. There are a number of other media where a similar record is needed, such as the Datakit VCS(R) and dial-up SLIP or PPP. I think I'd prefer a media address RR, with a subtype field first. I understand why in some cases one might opt for different records (and the matter is discussed in the RFC for an Andrew File System RR), but I'd vote differently than did the authors. My reasoning is simple: there are, I think, many different media for which the concept is applicable. If the vendor supports media address, I can create my own subtypes; it's much harder to add new RR types without the vendor's name server source. Second, it isn't clear to me who should be using the Route Through RR. Under what circumstances should a router do this (expensive) query? When there's no route to the host? To the network? What if the router doesn't have a direct link to the preferred forwarding host? Route towards is, and hope that the next hop knows enough to use the new record? I'm not saying RT is a bad idea, or hasn't been thought through; I am saying that I'd like to see some discussion on how it's intended to be used in a real Internet. --Steve Bellovin smb@ulysses.att.com