Re: Port scan from facebook

[Guillaume Ross <guillaume () binaryfactory ca>]

I'm not a Facebook user so I can't easily test, but is it possible that Facebook has anti-spam and anti-botnet 
processes that will scan your IP in order to know if it is an open proxy?
Maybe that happens when you have an office with NAT and multiple users coming from the same IP.

Guillaume

On 2012-08-09, at 1:15 PM, Wynn Fenwick <wynn () fenwicks ca> wrote:

> Shaun,
>
> What IPS is it? 
> "Coming from facebook" -- how is it determining that?
> What ports are being hit?
>
> Sometimes geolocation software will try multiple datagrams to your originating IP to assess the fastest data centre 
> from which to deliver content to the requestor, but it is usually not spread across multiple TCP ports to my 
> knowledge. The stimulus is likely a browser on your PC and your source IP is not known to Facebook (today).
>
> Another explanation is that numerous outbound TCP connections from an ephemeral source port will generate return 
> SYN-ACK packets coming back to those multiple source ports... so perhaps your "IPS" isn't very state-aware. If the 
> destination ports are > 1024 and are in sequence, then its likely that. 
>
> Else it would be interesting to see the answers above.
>
> W
>
>
> On 07/08/2012 4:55 PM, Shaun Curry wrote:
> > I have noticed some weird “stuff” coming from facebook.  My IPS blocked a “Probable Port Scan” from a facebook 
> > address going directly to an internal machine.  Has anyone dealt with this before?  How do I stop it without totally 
> > blocking facebook?
> >  
> > Shaun
> >
> >
> > _______________________________________________
> > Pauldotcom mailing list
> > Pauldotcom () mail pauldotcom com
> > http://mail.pauldotcom.com/cgi-bin/mailman/listinfo/pauldotcom
> > Main Web Site: http://pauldotcom.com
>
> _______________________________________________
> Pauldotcom mailing list
> Pauldotcom () mail pauldotcom com
> http://mail.pauldotcom.com/cgi-bin/mailman/listinfo/pauldotcom
> Main Web Site: http://pauldotcom.com

_______________________________________________
Pauldotcom mailing list
Pauldotcom () mail pauldotcom com
http://mail.pauldotcom.com/cgi-bin/mailman/listinfo/pauldotcom
Main Web Site: http://pauldotcom.com