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Lecture 2
- Internet evolution (part 2)
D.Sc. Arto Karila
Helsinki Institute for Information Technology (HIIT)
[email protected]
11.09.2012
M.Sc. Mark Ain
Helsinki Institute for Information Technology (HIIT)
[email protected]
T-110.6120 – Special Course in Future Internet Technologies
1
Evolutionary approaches
Architectural
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DNS (~1982)
EGP (precursor to BGP, ~1982)
TCP congestion control (mid-late 1980’s)
CIDR (~1993)
NAT (early 1990’s)
IPv6 (first RFC 1995, Internet standard 1998)
IPSEC (1995)
Mobile IP (~1996)
MPLS (~1996)
DiffServ / IntServ (~1998)
HIP (~1999, first RFC 2006)
BGPSec (mid 2000s)
DNSSec (~2004, first deployed at root level ~2010)
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Network Address Translation
(NAT) – 4 types
 Problem: address space exhaustion
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Network Address Translation
(NAT) – 4 types
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Network Address Translation
(NAT) – 4 types
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Network Address Translation
(NAT) – 4 types
 NAT is ugly, breaks E2E… but it works.
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IPv6
 Problem:
address space exhaustion
 IPv6 was born in 1995 after long work
 There are over 30 IPv6-related RFCs
 The claimed improvements in IPv6 are:
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Large 128-bit address space
Stateless address auto-configuration
Multicast support
Mandatory network layer security (IPSEC)
Simplified header processing by routers
Efficient mobility (no triangular routing)
Extensibility (extension headers)
Jumbo packets (up to 4 GB)
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IPv6
 Major
operating systems and many ISPs
support IPv6
 The use of IPv6 is slowly increasing in
Europe and North America but more
rapidly in Asia
 In China, CERNET 2 runs IPv6,
interconnecting 25 points of presence in
20 cities with 2.5 and 10 Gbps links
 IPv6 really only solves the exhaustion of
Internet address space
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IPv6
?
Planned
Actual
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IPSec
 Problem:
security
 IPSec is the IP-layer security solution of
the Internet to be used with IPv4 and IPv6
 Authentication Header (AH) only protects
the integrity of an IP packet
 Encapsulating Security Payload (ESP)
also ensures confidentiality of the data
 IPSec works within a Security Association
(SA) set up between two IP addresses
 ISAKMP (Internet Security Association and
Key Management Protocol) is a very
complicated framework for SA mgmt
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Encapsulating Security
Payload (IPv4)
Original IPv4 Header
Security Parameter Index (SPI)
Sequence Number
Coverage of
Authentication
ESP
Header
UDP/TCP Header
Coverage of
Confidentiality
ESP
Payload
Data
Padding
Pad Len
Next Hdr
Authentication Data
ESP
Trailer
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Encapsulating Security
Payload (IPv6)
Original IPv6 Header
Hop-by-Hop Extensions
Security Parameter Index (SPI)
Sequence Number
Coverage of
Authentication
End-to-End Extensions
UDP/TCP Header
Coverage of
Confidentiality
ESP
Header
ESP
Payload
Data
Padding
Authentication Data
ESP
Trailer
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Mobile IPv4
 Problem:
mobility
 Basic concepts:
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Mobile Node (MN)
Correspondent Node (CN)
Home Agent (HA)
Foreign Agent (FA)
Care-of-Address (CoA)
 The


following can be problematic:
Firewalls and ingress filtering
Triangular routing
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Mobility Example:Mobile IP
Triangular Routing
Ingress filtering causes problems for IPv4
(home address as source), IPv6 uses CoA
so not a problem . Solutions:
Correspondent
(reverse tunnelling) or
Host
route optimization
Foreign agent left
out of MIPv6. No special
support needed with
IPv6 autoconfiguration
DELAY!
Foreign Agent
Home Agent
Care-of-Address (CoA)
Mobile Host
Source: Professor Sasu Tarkoma
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Ingress Filtering
Packet from mobile host is deemed "topologically
incorrect“ (as in source address spoofing)
Correspondent Host
Home Agent
With ingress filtering, routers drop source addresses that are
not consistent with the observed source of the packet
Source: Professor Sasu Tarkoma
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Reverse Tunnelling
Correspondent
Host
Firewalls and ingress
filtering no longer a problem
Two-way tunneling leads to
overhead and increased
congestion
DELAY!
Router
Home Agent
Mobile Host
Care-of-Address (CoA)
Source: Professor Sasu Tarkoma
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Mobile IPv6 Route Optimization
CH sends
packets using routing header
Correspondent
Host
Secure tunnel (ESP)
Home Agent
First, a Return Routability test
to CH. CH sends home test and CoA
test packets. When MH receives both,
It sends the BU with the Kbm key.
Router
MH sends a binding update to CH
when it receives a tunnelled packet.
Mobile Host
Source: Professor Sasu Tarkoma
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Differences btw MIPv6 and MIPv4
 In MIPv6 no FA is needed
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(no infrastructure change)
Address auto-configuration helps in acquiring CoA
MH uses CoA as the source address in foreign link, so
no problems with ingress filtering
Option headers and neighbor discovery of IPv6
protocol are used to perform mobility functions
128-bit IP addresses help deployment of mobile IP in
large environments
Route optimization is supported by header options
Source: Professor Sasu Tarkoma
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Extension Headers
CN to MN
MN to CN
MH
Upper Layer
headers
Data
Mobility Header
MH Type in Mobility Header: Binding Update,
Binding Ack, Binding Err, Binding refresh
MN, HA, and CN for Binding
Source: Chittaranjan Hota, Computer Networks II lecture 22.10.2007
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(G)MPLS
 Problems: scalable transport, QoS, resource
usage, business incentives etc.
 (Generalized) Multi-Protocol Label Switching
 Layer 2.5 protocol
 High-performance transport of any layer 3 protocol
over any layer 2 data link over any layer 1 medium
 Routing via short path labels (path switching)
 Layer 2 and layer 3 services (e.g. PtP and PtMP VPN)
 Routing implemented in hardware (i.e. switching);
much faster than IP longest-prefix matching
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(G)MPLS
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QoS
 Problem: need better traffic control, satisfy
business incentives, better services etc.
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DiffServ
 Differentiated Services (DiffServ, RFC 2474) redefines
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the ToS octet of the IPv4 packet or Traffic Class octet of
IPv6 as DS
Allows operators to control treatment of packets but
does not guarantee any particular level of service or
policy adherence across network boundaries.
The first 6 bits of the DS field are used as Differentiated
Services Code Point (DSCP) defining the Per-Hop
Behavior of the packet
DiffServ is stateless (like IP) and scales
Service Profiles can be defined by ISP for customers and
by transit providers for ISPs
DiffServ is very easily deployable and could enable well
working VoIP and real-time video
Unfortunately, it is not used between operators
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IntServ
 Integrated Services
 Unlike DiffServ, IntServ reserves network
resources and attempts to guarantee
conditions of network flow end-to-end
 However, the process is complex, resource
intensive, and requires supportive cooperating
routers across all AS’s from source to sink.
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HIP
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Problems: mobility, security, multihoming,
IPv4/IPv6 interoperation etc.
Host Identity Protocol (HIP, RFC4423) defines a
new global Internet name space
The Host Identity name space decouples the
name and locator roles, both of which are
currently served by IP addresses
The transport layer now operates on Host
Identities instead of IP addresses
The network layer uses IP addresses as pure
locators (not as names or identifiers)
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HIP Architecture
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HIP
 HIs
are self-certifying (public keys)
 HIP is a fairly simple technique based on
IPSEC ESP and HITs (128-bit HI hashes)
 HIP is ready for large-scale deployment
 See http://infrahip.hiit.fi for more info
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Base exchange
• Based on SIGMA family of key exchange
protocols
Select precomputed R1. Prevent DoS.
Minimal state kept at responder!
Does notstandard
protect against
replay Diffieattacks.
authenticated
Initiator
solve
puzzle
Responder
Hellman key exchange for
session key generation
I1
HIT , HIT or NULL
R1
HIT , [HIT , puzzle, DH , HI ]
I2
[HIT , HIT , solution, DH ,{HI }]
R2
I
R
I
R
I
R
R
R sig
I
I sig
[HIT , HIT , authenticator]
I
R
sig
verify,
authenticate,
replay protection
User data messages
ESP protected TCP/UDP, no explicit HIP header
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HIP Mobility
 Mobility
is easy – retaining the SA for ESP
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HIP in Combining IPv4 and IPv6
 An
early demo seen at L.M. Ericsson
Finland (source: Petri Jokela, LMF)
IPv4
access
network
WWW Proxy
HIP CN
Internet
HIP MN
IPv6
access
network
Music Server
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BGPSec and DNSSec
 Problem: security (within two critical architectural
solutions)
 BGP Security Extensions:
 Authentication of inter-AS BGP data via Resource
Public Key Infrastructure (RPKI) i.e. digital signatures
 Does NOT provide confidentiality or guaranteed
availability
 Provides limited protection against certain misorigination attacks
 Not widely implemented
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BGPSec and DNSSec
 DNS Security Extensions:
 Authentication and integrity (of DNS query
results) via digital signatures
 Does NOT provide confidentiality or guaranteed
availability
 Protects against e.g. cache poisoning and other
forgeries
 Not widely implemented
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Key limitations, solutions,
underlying ossifications
Limitation(s)
Name-address translation
Solution(s)
DNS
Key underlying ossification(s)
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Network vs. human-friendly naming dichotomy
Scalability, routing inflexibility,
combined addressing and transport
TCP/IP, MPLS
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Endpoint-centrism
Rigid core protocol stack
Congestion
TCP congestion control
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Lack of built-in protocol-independent QoS
Rigid core protocol stack
Traffic control
BGP, IGPs + EGPs
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Endpoint-centrism
Send-receive communication paradigm
Address space exhaustion
CIDR, NAT, DHCP etc.
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IPv4
Mobility, multihoming
MIP, HIP
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Endpoint-centrism
Rigid core protocol stack
QoS
Diffserv + Intserv
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Lack of built-in protocol-independent QoS
Rigid core protocol stack
Security
Various (e.g. DNSSec,
BGPSec, and many
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Endpoint-centrism
Send-receive communication paradigm
others!)
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Rigid core protocol stack
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Evolutionary approaches
Application-level
Scalable content delivery
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3.
Security (confidentiality, anonymity, authentication etc.)
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3.
DHTs (~2001)
P2P networks
CDNs (e.g. Akamai)
Asymmetric crypto (e.g. RSA ~1977 or ~1973, DH ~1976)
PGP (~1991)
SSL/TLS (mid-1990’s, late-1990’s)
PKI (1990’s)
VPNs E.g. PPTP (~1999)
Wireless security e.g. WPA/WPA2/EAP (late 1990’s and beyond)
Tor (mid 2000’s)
Cloud computing
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Distributed Hash Table (DHT)
 Distributed Hash Table (DHT) is a service for storing
and retrieving key-value pairs
 There is a large number of peer machines
 Single machines leaving or joining the network have
little effect on its operation
 DHTs can be used to build e.g. databases (new
DNS), or content delivery systems
 BitTorrent is using a DHT
 The real scalability of DHT is still unproven
 All of the participating hosts need to be trusted (at
least to some extent)
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DHT
 The
principle of Distribute Hash Table
(source: Wikipedia)
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Overlay Routing
 In overlay routing the topology is formed over an
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underlying (usually IP) network
DHTs are examples of overlay routing
DHT techniques can be utilized e.g. in
implementing non-hierarchical rendezvous
An example of DHT-based solutions is the
Content Addressable Network (CAN)
CAN is based on a d-dimensional Cartesian
space, each node having a coordinate zone that it
is responsible for
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CAN
 A two-dimensional example
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Chord Ring
 Greedy forwarding (cmp w/ ROFL)
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Pastry DHT
 An example with hexadecimal identifiers
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P2P networks & CDNs
 Napster, Gnutella, BitTorrent (also utilizes
DHT) etc.
 Akamai CDN
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Security
 Confidentiality, anonymity, authentication
etc.
1.
2.
3.
4.
5.
6.
7.
Asymmetric crypto (e.g. RSA ~1977 or ~1973,
Diffie-Hellman ~1976)
PGP (~1991)
SSL/TLS (mid-1990’s, late-1990’s)
PKI (1990’s)
VPNs e.g. PPTP (~1999)
Wireless security e.g. WPA/WPA2/EAP (late
1990’s and beyond)
Tor (mid 2000’s)
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Cloud computing
 Computing resources are delivered via the
network
 “x”aaS i.e. “x” as a service
 E.g. software, storage, processing etc.
 Goal is to achieve resourcefulness and
efficiency via computing economies of scale
 Examples:
 Amazon, Apple, Google etc.
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For next week…
 READ (lecture 3):
 M. Handley. 2006. Why the Internet only just works. BT
Technology Journal 24, 3 (July 2006), 119-129.
DOI=10.1007/s10550-006-0084-z
http://dx.doi.org/10.1007/s10550-006-0084-z
 READ (lecture 4):
 Van Jacobson, Diana K. Smetters, James D. Thornton, Michael F.
Plass, Nicholas H. Briggs, and Rebecca L. Braynard. 2009.
Networking named content. In Proceedings of the 5th
international conference on Emerging networking experiments and
technologies (CoNEXT '09). ACM, New York, NY, USA, 1-12.
DOI=10.1145/1658939.1658941
http://doi.acm.org/10.1145/1658939.1658941
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Thank you for your attention!
Questions? Comments?
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