zotob - blocking tcp/445

Thu Aug 18 13:45:32 UTC 2005

On Aug 17, 2005, at 11:03 PM, routerg wrote:

> What if you are a transit provider that serves ebay, yahoo, and/or
> google and the worm is propogating over TCP port 80?

No one is suggesting that anyone suspend reason when making a  
decision to temporarily, or permanently for that matter, block  
packets with a specific port setting. It is a unreasonable stretch to  
imagine a transit provider, serving Ebay, Yahoo, and/or Google, who  
will have a staff unreasonable enough to block TCP/80 to halt a virus  
from spreading.

> Where will the filtering end?

The "slippery slope" defense has never stood in logical arguments, I  
don't understand why it should stand anywhere else. Once again, no on  
is asking anyone to suspend reason when making decisions. No on is  
making the statement "You must block ports used by virii of any  
magnitude, permanently without thought or investigation.". It was  
suggested that for outbreaks of significant size and severity,  
networks should issue temporary blocks on ports with little  
legitimate use. Expanding that suggestion to encompass more is being  
disingenuous to the original intent of the suggester

> Is your NSP/ISP responsible for filtering virii, spam, phishing?

ISPs are held accountable by their customers, whether rightfully or  
wrongfully, for virii, spam, and phishing. Customers expect their ISP  
to investigate, filter, and otherwise secure their connection.

We are held accountable for the traffic we source. I feel comfortable  
exercising some caution with traffic which is destined to me,  
especially if it is going to create an issue where other networks  
will hold me accountable for the fallout.

As someone eluded to earlier in the thread, customers expect to  
receive the traffic they want, and they expect their provider to  
prevent that which they did not request. Problems, support calls, and  
differences of opinion happen on the edge where those desires are not  
codified. 