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Re: DNS gurus: What is the max length of a TXT rec ords?

2004-02-09 08:55:56
In <00c701c3ef24$6b3fa4a0$020a0a0a(_at_)patch> "Sam Norris" 
<Sam(_at_)ChangeIP(_dot_)com> writes:

No matter what any UDP DNS message can also be a max of 512 bytes ... Thus
the reason for the 255 char limit on TXT records.

Well, yes, but I guess I was assuming that you could have a text
record in the 450-500 byte range (depending on other DNS data).  Text
records that go beyond that size I had assumed would switch to TCP.

The point is that instead of having a recommendation that SPF records
SHOULD be well below 500 bytes, I have learned that SPF MUST be below
256 bytes.  And that means that AOL can't double the size of their SPF
record without breaking it up with include: mechanisms.


Maybe this isn't news to others, but it is news to me.


-wayne

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