nanog mailing list archives

Re: UDP/123 policers & status


From: Bottiger <bottiger10 () gmail com>
Date: Sat, 28 Mar 2020 15:29:44 -0700


but why isn't BCP 38 widely deployed?


Because it costs time and money. People have been asking for it to be
implemented for decades. It is never going to be deployed on every network.

What fraction of the
world does implement BCP 38?


 Not enough. Everyone has to use it for it to work. Otherwise the hackers
will still find a network that doesn't have it.

I'd also be interested in general background info on DDoS.  Who is DDoS-ing
whom and/or why?  Is this gamers trying to get an advantage on a
competitor?
Bad guys making a test run to see if the server can be used for a real
run?


Most motivations for attacks can't be traced. But this is not just a gaming
problem. It is used to extort businesses for money, destroy competitors,
shutdown government critics, fame.

 Is DDoS software widely available on the dark web?


You don't need the dark web. It is widely available on Github like most
other attack types.

https://github.com/search?q=ntp+ddos

Broken protocols need to be removed and blacklisted at every edge. Pushing
the responsibility to BCP38 is unrealistic.


On Mon, Mar 23, 2020 at 7:43 AM Hal Murray <
hgm+nanog () ip-64-139-1-69 sjc megapath net> wrote:

Steven Sommars said:
The secure time transfer of NTS was designed to avoid amplification
attacks.

I work on NTP software (ntpsec).  I have a couple of low cost cloud
servers in
the pool where I can test things and collect data.

I see bursts of 10K to several million packets "from" the same IP Address
at
1K to 10K packets per second.  Ballpark of 100 events per day, depending
on
the size cutoff.  I saw one that lasted for most of a day at 1K
packeets/sec.

All the packets I've seen have been vanilla NTP requests - no attempt at
amplification.  I'm only checking a very small fraction of the garbage.

I haven't seen any pattern in the target IP Address.  Reverse DNS names
that
look like servers are rare.  I see legitimate NTP requests from some of
the
targets.

Would data be useful?  If so, who, what, ... (poke me off list)

I don't see any good solution that a NTP server can implement.  If I block
them all, the victim can't get time.  If I let some fraction through, that
just reduces the size of the DDoS.  I don't see a fraction that lets
enough
through so the victim is likely to get a response to a legitimate request
without also getting a big chunk of garbage.  I'm currently using a
fraction
of 0.  If the victim is using several servers, one server getting knocked
out
shouldn't be a big deal.  (The pool mode of ntpd should drop that system
and
use DNS to get another.)

If NTS is used, it would be possible to include the clients IP Address in
the
cookie and only respond to requests with cookies that were issued to the
client.  That has privacy/tracking complications.

----------

I don't want to start a flame war, but why isn't BCP 38 widely deployed?
Can
somebody give me a pointer to a talk at NANOG or such?  What fraction of
the
world does implement BCP 38?

I'd also be interested in general background info on DDoS.  Who is
DDoS-ing
whom and/or why?  Is this gamers trying to get an advantage on a
competitor?
Bad guys making a test run to see if the server can be used for a real
run?
Is DDoS software widely available on the dark web?  ...





--
These are my opinions.  I hate spam.





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