BCP38 [Was: Re: TWC (AS11351) blocking all NTP?]

[Jason_Livingood at cable.comcast.com (Livingood, Jason)]

>>Can somebody explain to me why those who run eyeball networks are able
>> to block outbound packets when the customer hasn't paid their bill,
>> but can't seem to block packets that shouldn't be coming from that
>> cablemodem?
>
>i suspect the non-payment case is solved at a layer below three

In a DOCSIS network the source address verification (as Tony said) is
typically done on the CMTS IIRC. Turning a customer off for non-payment is
done in an accounts management / billing system.

While I am sure continuing to agree with each other that spoofing is bad,
we lack actionable data. ;-) As I said in another thread, I think someone
/ some group needs to invest to collect actual data and share the results
openly. 

So any volunteers out there? I?m sure there are lots of ways to underwrite
independent research on the subject (contact me off-list).

Jason