A records like MX?

[Kevin Darcy]

SRV records are a more general method for doing this. In addition to
"preference" fields, SRV records also have "weight" fields, and can even
specify a port number for the service.

The downside is that no HTTP clients support SRV records yet (see
http://bugzilla.mozilla.org/show_bug.cgi?id=14328 for an attempt to get
this support added to Mozilla).

Without SRV, there is no good way to provide DNS-based automatic failover
for anything other than mail exchangers. You can certainly define a
"fixed" rrset-order for a particular name on all of the servers you
control, but what about other servers that cache the answer and then give
it back out in "round-robin" order? You can combat this behavior somewhat
by reducing the TTL values on your records to ridiculously low values,
but this is highly inefficient and will annoy other people on the Net,
since it will make their nameservers work much harder than they really
should have to, resolving your names over the Internet.

The only decent solutions right now are: a) mirror the website to
different boxes and serve it up equally, or b) buy an expensive L3
solution that frontends both webservers behind a single address.


- Kevin

Skeeve Stevens wrote:

> I was wondering with Bind 9... or some other way to do this.
>
> MX records can have a priority i.e.
>
> MX 10 mail1
> MX 20 mail2
>
> Is this possible for A records?
>
> I want to have a webserver on an A record i.e. 1.1.1.1 and if for some
> reason 1.1.1.1 is uncontactable it would rollover to 2.2.2.2
>
> Rotary DNS where you can do:
>
> www A 1.1.1.1
> www A 2.2.2.2
>
> Doesn't do what I want to do because it uses 2.2.2.2 regardless... I
> ONLY want it to use 2.2.2.2 if 1.1.1.1 is not accessible....
>
> Anyone know any methods to do this?