We are a small shop (read: no redundancies) and are planning on upgrading
our highly-leveraged BM server to 3.8. By highly-leveraged, I simply mean
that it is our single point of Internet connectivity, providing (most
significantly) outbound http proxy access, inbound reverse proxy access, a
number of NATs (most significantly our inbound e-mail addressing), and
typical firewall filtering.

While I have every confidence that the upgrade will go smoothly and there's
nothing to worry about, I'd like to figure out a reasonable/appropriate way
of maintaining those services (or suitable alternatives for them) while
performing the upgrade. (Specifically, I'd like to keep Internet
connectivity (though proxy-based access isn't completely necessary), the
essential NATs and at least rudimentary filtering.

I read a recent post about upgrading BM to a new machine, where the
suggestion was

>> Is it possible to install in the same tree, a new 6.5sp1a server, then
>> BM3.8 and configure it, leaving bm 3.6 running on the 5.1sp6 server.
>> Then, after all tests have passed, change the router config and proxy
>> config from the browser to use the new border 3.8?

>Yes, that's actually the preferred way of upgrading.

We have a spare machine that can be configured however is needed, whether it
be a Netware installation or something else... The above solution doesn't
match us exactly, however, as our spare is just a spare - it's the
already-in-use machine that we want to upgrade.

So any ideas or best practices? Do we install a whole new Netware/BM
server? If so do we mimic the name and ipaddress of the existing machine
and essentially just try to swap it in when we are ready to upgrade, take
the current machine offline, upgrade it and swap back? Should we introduce
a 'new' server to the network, changing all of our router information on the
network? Is there a better/simpler solution?

Many thanks for any advice!