netnerds.net » 2006

30May/069

TCP/IP Name Resolution Order

I found this gem in Addison Wesley's Inside WIndows Server 2003:

A simple way to remember the order in which TCP/IP uses these tools is the phrase "Can We Buy Large Hard Drives?" The first letters are keys for cache, WINS, Broadcast, Lmhosts, Hosts, and DNS.

Update: I just found the DNS query resolver behavior in the O'reilly book "DNS on Windows Server 2003":

1.The resolver first checks its local cache, which is systemwide (and therefore shared by all applications calling the resolver). If the desired record is not in the cache, the resolver has to send at least one query to a name server.
2. The resolver queries the first name server of the preferred network adapter and waits just one second.
3. If no answer is received, the resolver resends the query simultaneously to the first name server configured for each network adapter and waits two seconds. If the host has only one network adapter, this step is skipped.
4. If no answer is received, the resolver resends the query simultaneously to all name servers configured for all adapters and waits two seconds.
5. If no answer is received, the resolver resends the query simultaneously to all name servers configured for all adapters and waits four seconds.
6. If no answer is received, the resolver resends the query simultaneously to all name servers configured for all adapters and waits eight seconds.
7. If after all this time no name server has returned an answer, the resolver gives up and an error is returned to the application.

Posted by: Chrissy Filed under: Networking 9 Comments

16May/064

Woohoo!! A few months ago, I contributed to onmac.net, hoping that somone would be motivated by the nearly $13,000 offered up to get Windows running on a MacBook. They did, and two weeks later, Apple came out with Bootcamp which did the same thing but better. I swore that THE DAY the 13 inch widescreen Macbook came out, I'd buy one.

Today, my friend Bun told me that Apple released the new 13 inch widescreen MacBook. I called the Apple store down near Union Square in San Francisco to make sure they had some. The guy returned my call at 10:55 and I was on my way at 10:56. I got there, ordered the black one with an extra gig of RAM and waited about 30 minutes to pay for it. Just as I was paying, the manager made an announcement that they were all out of black MacBooks. My order was already placed, though, right? YEP! I got the LAST black Macbook at that Apple store. I held it closely, hoping not to get jumped by rabid Apple fans (there were a few angry ones demanding to see the manager..like that'd help).

Sooo.. I now own this beauty

13.3-inch widescreen display, 1280 x 800 resolution, 2.0GHz Intel Core Duo1, 1.25GB memory SODIMMs, 80GB SuperDrive (DVD±RW, CD-RW) !!!

Posted by: Chrissy Filed under: General 4 Comments

15May/0616

SQL: 6.5 Compatibility in SQL Server 2005

This isn't a very common scenario, but I figured I'd write about it anyway. We recently implemented a Windows 2003 Active Directory domain at work. I suggested to my employer that, going forward, we only install SQL Server 2005 when we need a database server (phasing out 2000). I'd also suggested consolidating a couple of our older servers (7 and 2000) into one.

So I setup a test SQL Server 2005 server in our lab environment. I migrated a few of our most active databases using two different methods: detach -> reattach and backup -> restore. Both worked perfectly well. Actually, the detach -> reattach complained about possible corrupt indexes but it was a false alarm. Other than that, things went very smoothly.

Apparently, one of the databases I migrated has been around for quite some time. It showed up as SQL 6.5 Compatible and lacked most of the options in the Management Studio.

SQL Server 6.5 Compatibility mode in SQL Server 2005 Management Studio

I assumed that this particular database started out on a SQL 6.5 machine which was then upgraded to SQL 7 and SQL 7 kept it in 6.5 compatibility mode. Still, the database worked and I was able to issue a few queries to it without a problem. I wondered if perhaps SQL Server 7 or 2000's Enterprise Manager would allow me to manage that SQL 6.5 database in the GUI but I couldn't even connect.. SQL 2005 requires that you connect via the management studio to administer the machine graphically. Query Analyser connected just fine though it took a little bit of tweaking from the SQL 7 machine. Initially, I ran into this error:

Named Pipes Connection Broken. Alright, we'll avoid NetBIOS and try by IP.. perhaps that would force a TCP/IP connection. No dice. It just forced a TCP/IP over NetBIOS connection. I thought back to the days of SQL 7 and did the following, which worked: Start -> Programs -> SQL Server 7 -> Client Network Utility -> Add -> Server Alias: labsql2k5 | Network Library: TCP/IP | Server Name: 192.168.1.x

That worked like a charm. Initially, I wondered if the Named Pipes connection was breaking because the two SQL Servers are on different domains (that have a 2 way trust) but I had no problems connecting to a SQL Server 2000 machine over a truested domain -- no alias needed. SQL Server 2000's Query Analyser required no additional tweaking to connect to SQL 2005. This may be due to the fact that TCP/IP was listed as the first network protocol to attempt.

Posted by: Chrissy Filed under: SQL Server 16 Comments

1May/061

IIS: MD_CUSTOM_ERROR (6008)

I recently loaded up one of my servers and out of nowhere, I ran into this error:

Server Configuration Error
The server has encountered a configuration error attempting to process your request. The configuration parameter MD_CUSTOM_ERROR (6008) has an invalid value. Please contact the server administrator for assistance.

I searched the web but couldn't find anything useful. I then started exploring the website's configuration under IIS Properties and I received a similar error when loading up the tab "Custom Errors." I saw a malformed error (401;3 was pointing to C:\windows\help for some reason), set it to default and the site worked again.