RE: Network diversity Software diversity

From: []
Sent: Wednesday, January 24, 2001 9:47 PM

[ On , January 24, 2001 at 17:19:29 (-0800), Sean Donelan wrote: ]
> Subject: Network diversity Software diversity
> Using FreeBSD and BIND on *ALL* your name servers may be just as
> bad a practice as using Windows 2000 and Microsoft DNS on *ALL*
> your name servers. I still think NSI is taking a tremendous risk
> using identical servers for all their GTLD-servers, even though
> they are geographically distributed.

Yeah, I was going to mention that, but I thought I'd already been
preaching too much to the converted! :slight_smile:

Unless another name server, besides BIND8p7, can do SRV updates properly, I
don't think it is possible to build that heterogenous software environment,
when Win2K Active Directory is involved. In fact, even BIND8 has problems.
It's only possible, with WinNT4, because WinNT4 doesn't have [very] many
silly requirements and can live with a standard name server.

> You might try using UltraDNS on half your critical nameservers and
> BIND on the other half. And even using Solaris on some of the
> boxes and AIX or Linux, or NetBSD on the others. This is not because
> I think one or the other has a fatal flaw, but because software is
> a hard beast to manage. The idea behind diversity isn't you will
> never have an error. But the errors are unlikely to strike both
> servers at the same time.

Therein lies the rub -- adding extra complexity to your systems also
makes them more difficult to manage, prone to error, and subject to
interoperational problems.

Diversity of all forms definitely has its advantages, but it has its
costs too. The trick is to find a fair balance. :slight_smile:

In this case, at this time, that is not possible under Win2K. It's the MSFT
way or the highway ... However, if you think about it, this will definitely
delay MANY Win2K Data Center migrations.

Uhh, I highly doubt they have a requirement to run DDNS on the front ends. If all you're doing is serving up html pages without user authentication, Win2K is perfectly happy with its own internal account database. DDNS is a pre-req for AD, but AD is not a requirment. In fact, I would probably strip it off to save resources if all I was doing was pumping out pages. Furthermore, why would you run DDNS to map names to IP addresses for devices that should stay on static addresses? DDNS is used in Win2K for resource location, such as AD and the various role servers. None of those have any use outside on the Internet

(assuming of course they don't let you map a drive to their web servers, which by the way you used to be able to do to their FTP server many eons ago. I remember the fun of copying their FTP site with XCOPY from a mapped drive to a local drive with a 56K line [probably on both ends at the time] in between).

Reaching further back, I also remember NFS mounting the WUSTL archive to our brand new RS/6K in the comp sci department. Really drove home the idea of mounting NFS hard and the transparency of the link when the tape filled up using our 56K campus line over a weekend. Really pissed off the sys admin also. :slight_smile: Then again, thats when you had to be at least 18 to get on the Internet ...