(should this go to netbsd-help?)

Hello.
I am in need of developing a High Availability solution to my innermost 
problems, and I'd like to ask a few questions.

The goal may sound as follows:
   With the least cost (recycled hardware :) ) produce an HA server 
possibly secure and with load-balancing. The so-called server cluster 
can be connected to the rest of the net via a single network cable and 
has a single network address. IPv6 support is a welcome addition :)

To make it even clearer, I want the actual servers to be in a private 
network (like 10.*)

I know there are solutions to the problem under GNU/Linux; this is some 
sort of challenge to realize how much can be done in NetBSD (OpenBSD is 
fine too, if necessary). I might even write a document if successful ;)

Searching the mail archives didn't bring up enything I could understand.

I am browsing the /pkgsrc/net packages, quite aimlessly.
Apparently interesting are delegate, dhid, fping, nocol, pen. Can anyone 
give me some of their impressions?

Since the data the servers provide is shared, I need some sort of 
storage. I was thinking about a file server (yes, it's a SPF). If I 
understand correctly, coda does not fit because files are copied locally 
before they can be modified, and then they get sent back on close, 
databases' updates would then get spreaded after too much time. NFS3 has 
some problems (stale handles and such)... is there a NFS4 implementation 
for NetBSD? Or, do you have any better hints other than NFS4?

Another thing I think might not be good is the fact that the entrance 
(call it load balancer, entry point, NAT machine or whatever; it's the 
one with the public IP) is a SPF; is there any good way to fix it? I was 
thinking about the possibility to add a network switch between the 
incoming cable and the computer, adding another computer's network cable 
to the switch and use the newly added as a backup for the balancer 
(which is heartbeaten via, say, serial cable) but then problems might 
arise when only the serial goes down (2 NICs up with the same address) 
or when the NIC goes down (the serial still beats, 0 NICs up). Is there 
light at the end of the tun0?

This is all I could think so far. All suggestions are welcome.

Thank you for your attention.
	Paolo Torelli