In <[EMAIL PROTECTED]> [EMAIL PROTECTED] (Tim Shoppa) writes:

> Notice that many of the "naughty" clients get far naughtier if you
> do not respond to their polls.  It sucks, but that's how it is.

While I know that there *are* cases that naughty clients get worse if
you don't reply (e.g. the uwisc ntp incident), in practice for the ntp
pool, I have not found the case.

In most cases, blocking requests from badly behaving clients doesn't
change anything, other than save you outgoing bandwidth.  In some
cases, I have found that sending packets back to the client causes
ICMP port/host unreachable packets to be sent back, so blocking badly
behaving clients is a win.

Most of the badly behaving clients that was able to get information on
turned out to be bog standard ntp clients (typically linux clients)
behind a firewall.


Many people have less upload bandwidth than download bandwidth, so
blocking badly behaving clients saves you the important half of the
bandwidth usage.


-wayne
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