[f-nsp] ServerIronXL 16 or 24 port questions..

[Bjørn Mork]

"Emilia Lambros" <emilial at hostworks.com.au> writes:

> The way I understood it when I researched it and subsequently set up
> gslb, there needed to be ServerIrons at each location. 

Yes.  The ServerIrons need to measure the RTT between the real servers
an the clients, so you need a ServerIron in the path between every
server and client, preferably very close to the servers.  Hard to
imagine how to do this without having a ServerIron at each location.
But why not?  It's a great SLB box anyway.

>  Its smoke, mirrors and DNS.  The ServerIrons actually have to have DNS
> behind them to see the responses and change them if necessary, or they
> have to provide the DNS for that (sub)domain themselves and they change
> it if necessary.  They need to have control of the DNS in some way for
> glsb to work.  Hard to grasp the first time you hear it, but the
> ServerIrons can do DNS.

In theory.  I practice they can only handle A records, and they will
not respond at all to requests for anything else (at least they didn't
with 07.1.21 and earlier SW)! This means that you *must* have a real
DNS server behind the ServerIron to serve NXDOMAIN answers to e.g. 
AAAA requests, or clients supporting IPv6 will suffer a long delay
caused by DNS timeout.


Bjørn