How to do primary and alternate ip addresses for a server?

Re: How to do primary and alternate ip addresses for a server?

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Sorry for the delayed reply. I was out of the office yesterday and today.

The only way to do this with DNS data is to use a load balance record
in QuickDNS (Mac OS 8/9 only), or something similar. Without this,
which must be implemented by your DNS server in such a way that the
web browser doesn't have to know about the other IP address, DNS data
has no way to specify asymmetric load sharing.

To do this with QuickDNS Server for Mac OS 8/9, create a load balance
record in your zone (Edit menu, Insert Record submenu, Load Balance
Record). Give the record a hostname (e.g. "www" or "load") - the name
will have the zone name appended to it, just as in any other record's
name. Also, this name has much the same restrictions as a CNAME
record - it can't be the same as any other record's name, including
the name of the zone.

Then fill in the TTL, Interval, and Hostlife numbers. These are:

TTL: Time to live. Just like any other record, except for the load
balancing to work well, you generally want to set this to a low
number, such as 300 seconds.

Interval: This is the frequency at which QuickDNS checks each IP
address listed to make sure that there's a web server there, for the
sake of fault tolerance. Must be at least 30 seconds, and 30 seconds
is a good value.

Hostlife: Also used in the fault tolerance mechanism, this is the
length of time between successful "interval" checks before a given IP
is taken out of the rotation. Must be higher than the Interval
setting; 60 or 90 is generally a good number.

Now fill in the IP addresses of the web server. For each one, assign
a preference value. If you want the relative loads to be 99.44% and
.56%, then you can set these to 9944 and 56. Integers between 1 and
about 32000 are acceptable.

Since a load balance record is a delegated subzone, it must have its
own NS records. Choose which name servers to include, from the list
of servers currently connected. Note that, for this to work properly,
you must be connected to your DNS servers by name (in the connection
dialog), not by IP address.

That's all there is to the dialog. If you want to have multiple names
load balanced in exactly the same way, set up one of them as a load
balance record and create CNAME records for the rest.
____________________________________________________________________
Chris Buxton Men & Mice
cbuxton@menandmice.com We Make DNS Easy!

At 6:26 PM -0400 5/6/01, Robert J. Woodhead (AnimEigo) wrote:
>I have a server whose dns is 1.2.3.4 (for example). 99.44% of the
>time, when 1.2.3.4 is reachable, I want people to access the server
>at that IP address.
>
>The other .56% of the time, I'd like them to use the alternate IP
>address 9.8.7.6. How do I go about configuring DNS for this.
>
>The actual situation is this. I have two data links into the
>office; a wireless point-2-point connection (primary) and a DSL line
>(secondary). The router for the p2p connection is a nice linux box,
>and we think we can config it so that it masquerades IP and
>translates incoming requests on the DSL line to the actual IP
>addresses inside the office (and again on the way out). So each
>machine will have 2 ip addresses to the outside world.
>
>Best
>R
>--
>===========================================================
>Robert Woodhead, CEO, AnimEigo http://www.animeigo.com/
>===========================================================
>http://selfpromotion.com/ The Net's only URL registration
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