On Feb 3, 2014, at 10:49 AM, Geraint Jones <gera...@koding.com> wrote:

> We block all outbound UDP for our ~200,000 Users for this very reason

Actually, you could've (and should've) been far more selective in what you 
filtered via ACLs, IMHO.

What about your users who play online games like BF4?

I'm a big believer in using ACLs to intelligently preclude 
reflection/amplification abuse, but wholesale filtering of all UDP takes 
matters too far, IMHO.

My suggestion would be to implement antispoofing on the southward interfaces of 
the customer aggregation edge (if you can't implement it via mechanisms such as 
cable ip source verify even further southward), and then implement a default 
ingress ACL on the coreward interfaces of the customer aggregation gateways to 
block inbound UDP destined to ntp, chargen, DNS, and SNMP ports only.

-----------------------------------------------------------------------
Roland Dobbins <rdobb...@arbor.net> // <http://www.arbornetworks.com>

          Luck is the residue of opportunity and design.

                       -- John Milton


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