TTimo, a suggestion (one you might have implemented already, but I’ll post it just to be sure): Obviously a “hard” limit on the number of servers in the master list will prevent triggering the client brower bug in 2.56.
However, as shown in the posts on page 2 of this thread, the vast majority of the server entries were generated from a small number of IP addresses. The systems at these addresses claimed to have hundreds of servers running. Whether this was done intentionally or accidentally is anyone’s guess.
In light of this it might be a better strategy to limit the number of master list entries per IP address as well. That way, it will be more difficult for these bogus servers to push the real ET servers off the list by spamming hundreds of entries. A limit of, for instance, 10 servers per IP address would be more than enough to retain all “real” servers and filter out most erroneous ones.
Just my 0.02.