In
Carl R said:
I can confirm that his console is NOT corrupt. The same exact thing
is happening with me.
I am unable to publish a single-line SPF record as it is too long.
You can copy and paste and, yet is gets the scroll bar at the bottom
and looks like it is going to work perfectly, BUT once you save it,
close it and reopen it IT IS TRUNCATED EVERY TIME. Nice feature.
This goes for Windows 2000 or Windows 2003 (with or without SP1).
Looks like we are stuck with multiple records and multiple "includes"
to get this thing working.
"you would think someone would actually test this stuff before rolling
it out"
Ok, you got my curiosity. I tried testing it with a large set of data,
specifically text I copied from a website and pasted it into word, got a
character count, 1562 (with spaces), and pasted it into a TXT record. It
truncated it to 251. So I thought let me remove all the spaces out of the
text passage that I copied. I got 1061 characters. I copied and pasted that
text without spaces, into the TXT record, and it truncated it to 56.
Hmm... So then in Word, I dropped the character count to 255 without spaces.
I copied and pasted that, and it WORKED. I added one more character, and it
truncated it. I tried it again and it deleted the record completely. I tried
it again, and it truncated it to 33 characters. Hmm, interesting. So if it
is longer than 255, it is will not take it and the system acts up on it.
Hmm. Now I know many records types, commands, such as SMTP commands, and
others, have a maximum length of 255, for that's the buffer size. Any
attempt to jam more than that is considered a buffer overflow.
So gouing on the 255 assumption and the system was trying to protect itself
and/or just follow the RFC, at the same time not bashing myself over the
head trying to say the operating system is nuts, or blaming Microsoft for
that matter, as you implied in your post, I did some research.
I found RFC 1035. I defines DNS RR types, but it didn't specifically mention
length about any specific record, but it did say a "Name" can only be 255.
The text data in a TXT is a "name" by it's definition, as I read from the
article and noted below from RFC 1035:
http://www.faqs.org/rfcs/rfc1035.html
=====================
2.3.4. Size limits
Various objects and parameters in the DNS have size limits. They are
listed below. Some could be easily changed, others are more
fundamental.
labels 63 octets or less
names 255 octets or less
TTL positive values of a signed 32 bit number.
UDP messages 512 octets or less
=====================
John had a point earlier on about keeping response records less than 512,
but that would be the total response of a query, meaning, if a query was for
an MX record, all the MX records for a zone will be returned. Hotmail and
Yahoo have over 512 in the response, but each record is barely a line long.
In this case, the TXT record is just that, a record, and has limitations
based on the RFC.
So, I would not bash Microsoft about this because they're just following the
RFCs, as are other DNS vendors. So I think you were a little quick to point
fingers without doing a little simple research on it to prove/disprove it.
Ace
