Speaker
Mr
John Heidemann
(USC/Information Sciences Institute)
Description
Distributed Denial-of-Service (DDoS) attacks continue to be a major
threat in the Internet today. DDoS attacks overwhelm target services
with requests or other "bogus" traffic, causing requests from legitimate users
to be shut out. A common defense against DDoS is to replicate the
service in multiple physical locations or sites. If all sites
announce a common IP address, BGP will associate users around the
Internet with a nearby site, defining the *catchment* of that
site. Anycast adds resilience against DDoS both by increasing capacity to the
aggregate of many sites, and allowing each catchment to contain attack
traffic leaving other sites unaffected. IP anycast is widely used for
commercial CDNs and essential infrastructure such as DNS, but there is
little evaluation of anycast under stress.
This talk will provide a *first evaluation of several anycast services
under stress with public data*. Our subject is the Internet's Root
Domain Name Service, made up of 13 independently designed services
(``letters'', 11 with IP anycast) running at more than 500 sites.
Many of these services were stressed by sustained traffic at 100x
normal load on Nov. 30 and Dec. 1, 2015. We use public data for most
of our analysis to examine how different services respond to the these
events. In our analysis we identify two policies by operators:
(1) sites may *absorb* attack traffic,
containing the damage but reducing service to some users, or (2) they may
*withdraw* routes to shift both legitimate and bogus traffic to other sites.
We study how these deployment policies result in different levels of
service to different users, during and immediately after the attacks. We also show evidence of *collateral
damage* on other services located near the attack targets.
The work is based on analysis of DNS response from around 9000 RIPE
Atlas vantage points (or "probes"), agumented by RSSAC-002 reports
from 5 root letters and BGP data from BGPmon. We examine DNS
performance for each Root Letter, for anycast sites inside specific
letters, and for specific servers at one site.
Summary
This talk will evaluate the event affecting many Root DNS servers on November 30, 2015, based on public data from RIPE Atlas and other sources.
| Talk duration | 30 Minutes |
|---|
Primary authors
Cristian Hesselman
(SIDN Labs)
Giovane C. M. Moura
(SIDN Labs)
Mr
John Heidemann
(USC/Information Sciences Institute)
Lan Wei
(USC/ISI)
Moritz Müller
(SIDN Labs)
Dr
Ricardo Schmidt
(University of Twente)
Wouter de Vries
(U. Twente)
