In <012001c407ae$cb416120$6401a8c0(_at_)hdev1> "Hector Santos"
<hsantos(_at_)santronics(_dot_)com> writes:
It was also determined
that the usage of TXT records is low enough that there wasn't a need
to place them in a subdomain in order to keep the DNS queries under
512 bytes.
Small note: This should be a non-issue as most DNS resolvers should be
supporting truncated datagrams DNS responses with a fallback to TCP
streaming.
Yes, in theory it *should* be a non-issue. Unfortunately, we found
that there are all too many firewalls out there that think that TCP
port 53 traffic should not be allowed. Since almost 100% of all DNS
traffic goes via UDP, there is no reason to pass TCP DNS traffic and
since you can't reliably use TCP DNS, almost 100% of all DNS traffic
needs to go via UDP.
*sigh*
Yes, this is broken, but we need to consider the issue.
For sure, Microsoft CEP depends on it based as it even
documented the idea of split XML TXT records that need to be joined
(implying +512 bytes situations).
Well, I don't know what MS found during their investigations, but
Hotmail's C-ID records are split up via <indirect>'s. This means that
each of the four (4) required DNS queries are under 512 bytes each.
-wayne