On Tue, 10 Jun 1997, Robert E. Seastrom wrote:
4) It puts the onus for fail-over on the DNS server, which means one is going to be using very short TTL.
Suppose you run two nameds. One with an addr on provider A, and one with an addr on provider B. Each one responds with only the address from its respective provider. Suppose A goes down. Then (most) new folks won't be able to reach your A name server and so won't even be trying your A address. (You have to assume here that your site isn't popular enough to be in most ISPs caches already... because if it were that popular you probably can get PI space anyhow.) This violates the rules of DNS however. Those nameservers can't claim to be authoritative and yet yield different answers. (And Paul is probably disappointed I'm suggesting it!) But going to this extreme is probably not even necessary any longer. MSIE 3 will skip past dead addresses and try all A records. Netscape communicator is supposed to do that (I haven't tested). And Squid will try all addresses. That leaves navigator 3.0. Give it six months. Dean