VeriSign Internet Defense Network

Deepak Jain deepak at
Tue May 31 19:06:46 UTC 2011

Let's not ignore the value of DNS with a short ttl time. It may not be "as quick" as a BGP adjustment, but serves to provide a buttressed front-end IP that can restore service "instantly" [faster than getting someone on the phone to coordinate the change, etc]. 

Disclaimer: We provide a service for our customers that does substantially this sort of DDOS mitigation.


> Normally when mitigation is put in place, they advertise a  more
> specific prefix from as26415, scrub the traffic and hand it back to you
> over a gre tunnel...
> Obviously some design consideration goes into having services in
> prefixes you're willing to de-agg in such a fashion... I'd also
> recommend advertising the more specific out your own ingress paths
> before they pull your route otherwise the churn while various ASes
> grind through their longer backup routes takes a while.
> On May 30, 2011, at 7:43 AM, Rubens Kuhl wrote:
> > ms made by the product descriptions seem suspect to me.
> >>
> >> it claims to be "Carrier-agnostic and ISP-neutral", yet "When an
> event is
> >> detected, Verisign will work with the customer to redirect Internet
> traffic
> >> destined for the protected service to a Verisign Internet Defense
> Network
> >> site."
> >>
> >> anyone here have any comments on how this works, and how effective
> it will be
> >> vs. dealing directly with your upstream providers and getting them
> to assist
> >> in shutting down the attack?
> >
> > Anyone willing to announce your IP blocks under attack, receive the
> > traffic and then tunnel the non-attack traffic back to you can
> provide
> > such services without cooperation from your upstreams. I don't know
> > the details about this particular provider, such as if they announce
> > your blocks from yours or theirs ASN, if they use more specifics,
> > communities or is simply very well connected, but as BGP on the DFZ
> > goes, it can work.
> >
> > You might need to get your upstreams to not filter announcements from
> > your IP block they receive, because that would prevent mitigation for
> > attack traffic from inside your upstream AS.
> >
> > (RPKI could also be a future challenge for such service, but one
> could
> > previously sign ROAs to be used in an attack response)
> >
> > Rubens
> >

More information about the NANOG mailing list