Split-Brain DNS Clarification
I don’t claim to be a DNS expert, but I
think Michael Dragone’s article—”Split-
Brain DNS” (September 2008, InstantDoc
ID 99772)—needs clarification. If a
domain has sites that exist internally and
externally and will have both internal and
external users, you must have records
on both the internal and external zones.
Otherwise, internal queries for an external
site that doesn’t exist in the internal
zone will fail. The internal DNS server
finds the zone locally, and when it doesn’t
find the host you’re looking for, it gives up
without forwarding up to a higher name
server.
—John Meola
In the article, I assume that an external zone
is already set up and that an internal zone
is being added. Although it’s not specifically
stated that you must add additional
host records for your domain and not just
a record for www (as the example shows),
such is indeed the case. Note that these
zones don’t have to—and likely won’t—
identically match. Your internal zone is likely
to resolve queries to private IP addresses
instead of public IP addresses as your external
one will, and you might not need all
the host names in both. For example, there
would be little need to resolve “remote
vpnaccess.mydomain.com” internally.
—Michael Dragone
Do We Really Want Dogfood?
Has it occurred to anyone that the phrase
dogfooding (a vendor’s practice of using the
same products it sells to customers) implies
that the product is dogfood and that the
customers are dogs? Maybe we should
consult an oracle before we dream up more
industry-standard terms ... or at least a common
heckler.
—Thomas Inwood
64-Bit Champion
I was dismayed to read Ken Spinks’s letter in
the October 2008 edition of Windows IT Pro
because it reinforced a common misconception
about 64-bit systems. He writes that he
bought a lesser PC for his wife because he
“didn’t want extra (i.e., 64-bit related) problems
with printers, scanners, cameras, or
software.” The assumption is that 32-bit drivers
will be more prevalent and better than
their 64-bit counterparts. However, the exact
opposite is true.
For Windows Vista logo certification,
Microsoft required only 64-bit drivers, which
means these were the only drivers that
experienced the rigorous testing required for
certification. My personal experience bears
this out: My business laptop running the
64-bit version of Vista Ultimate works with
all my peripherals and is far more stable and
reliable than the 32-bit version of Vista Ultimate
that I run on my home PC. Mr. Spinks
could have still run a 32-bit version of Vista
on the upscale PC that he passed over. PCs
with 64-bit AMD or Intel processors are fully
backward-compatible and will run either a
32-bit or 64-bit OS.
—Alan J. Walsh
Disabling Automatic SUA Startup?
I enjoyed John Howie’s “Move Apps from
UNIX to Windows with SUA” (September
2008, InstantDoc ID 99588). I’m considering using the feature in Vista, but I’m curious
whether Subsystem for UNIX-Based Applications
(SUA) must start up with Windows.
I’d like to disable automatic SUA startup at
system startup and instead have it launch
only when I run an SUA application. Can I
do that?
—Jonathan Hanson
SUA isn’t a traditional Windows service; it’s
an optional subsystem, started when the
system boots. In the days of Windows NT, both
the OS/2 and POSIX subsystems shipped “in
the box.” Now, POSIX is an optional extra. It’s
configured in the HKEY_LOCAL_MACHINE SYSTEM\CurrentControlSet\Control\Session
Manager\SubSystems\Option registry subkey
(of type REG_MULTI_SZ and value Posix). If
the registry entry is present, you’ll see another
subkey (under the same key) called Posix, which
contains the value %SystemRoot%\system32 psxss.exe. This is the POSIX subsystem executable,
which runs at startup. There’s no support
for starting it after the system has started.
—John Howie
PowerShell Knockout
I just want to commend Windows IT Pro on
Robert Sheldon’s fantastic PowerShell series
(“PowerShell 101,” February–July 2008). And
you capped it off in September with the fivepage
knockout “Managing AD User Accounts
with PowerShell” (InstantDoc ID 99760).
Articles like these are the reason I subscribe
to your magazine.
—Adeogun Adedamola
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