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Architectural Risks and Mitigations in IPv6


Information scope is limited, additional readings required. Presentation ... Prepend FF onto 3A:9E9A. Append the result to the SNMA Prefix FF02::1:FF3A:9E9A ... – PowerPoint PPT presentation

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Title: Architectural Risks and Mitigations in IPv6

Architectural Risks and Mitigations in IPv6
  • James R Lindley
  • Senior Computer Engineer
  • (Security Architectures)
  • IRS IT Security Architectures Engineering

  • Information scope is limited, additional readings
  • Presentation Organization
  • A SHORT review of the IPv6 Protocol Suite
  • Architectural Insecurities
  • Possible Mitigations

Features of Network Layer Protocols
  • Logical Addressing
  • Route Discovery
  • Quality of Service
  • Packet Header Structures
  • Fragmentation Methods
  • Supporting Protocols

How to Use 128 Bits
  • We really dont get 3.31038

32-bits 4,294,967,295
18,446,744,073,709,551,615 potential hosts
64 bits - Host
A /16 281,474,976,710,655 networks
IPv6 Address Types
  • Unicast
  • Address of a single interface
  • One to one delivery to single interface
  • Multicast
  • Address of a set of interfaces
  • One to many - delivery to all interfaces in the
  • Anycast
  • Address of a set of interfaces
  • One to one-of-many - delivery to the closest
    single interface in the set
  • No more broadcast addresses

Unicast IPv6 Addresses
  • Aggregatable Global Unicast Addresses (AGUA)
  • Link-local addresses
  • Site-local addresses (not SLA see later)
  • Unique Local Addresses (replaces Site-local)
  • Special addresses
  • Compatibility addresses
  • NSAP addresses (Network Service Access Point)

IPv6 Address Summary
  • Global
  • Typically begins with 2 or 3 (ARIN 26000)
  • Unique for the entire IPv6 Internet
  • Link-local
  • Begin with FE80
  • Unique for a single link
  • Site-local (deprecated)
  • Begins with FEC0
  • Local
  • Begin with FD00
  • Multicast
  • Begin with FF00

Multiple Addresses on a Node
  • Unlike IPv4, an IPv6 node always has multiple
  • Link-local, site-local, global, etc.
  • It is the job of the nodes protocol stack to
    decide most efficient address to use to reach the
  • Greatly simplifies routing

Assigning Interface Addresses
  • Two ways to assign addresses
  • Static assignment
  • Automatic assignment
  • via DHCP (stateful)
  • via autoconfiguration (stateless)
  • Static assignment will be challenging because of
    the address size
  • Automatic assignment will be much more common

Six Paths to an IPv6 Interface ID (Address)
  • Extended Unique Identifier (EUI-64) address
  • Randomly generated value (SeND)
  • A value assigned by a stateful address
    configuration protocol such as DHCPv6
  • Expanded IPv4 Address
  • A manually configured value
  • A value assigned during the establishment of a
    Point-to-Point Protocol connection

Extended Unique Identifier (EUI-64) address
  • Derived from IEEE MAC-48 address
  • Privacy considerations in host ID
  • MAC-48 structured address architecture makes
    range scanning easier

Randomly generated value (SeND)
  • RGV Randomly Generated Value
  • Sometimes AKA Cryptographically Generated Address
  • Greater privacy (RGV also used in EUI-64 privacy
  • Maximum range scanning difficulty due to
    unstructured address architecture
  • Loss of administrative address control

IPv6 Interface ID Configuration DHCPv6
  • Value assigned by a stateful address
    configuration protocol (i.e., DHCPv6)
  • Requires router Managed Address parameter
  • Requires DHCPv6 server and administration
  • May result in address assignment patterns that
    make range scanning easier

IPv6 Interface ID Configuration eXIPv4
  • Expanded IPv4 Address
  • Used with 4to6 and 6over4 and ISATAP tunneling
  • May reveal IPv4 use and address
  • May make U-Turn Attacks easier

IPv6 Interface ID Configuration Manual/PPP
  • Manually configured value
  • More labor required
  • Pattern establishment possible
  • Does not make best use of dynamic and automatic
    IPv6 address assignment tools
  • Value assigned during the establishment of a
    Point-to-Point Protocol connection
  • Used only with PPP
  • Found only with MODEM dialup connections

Stateless Autoconfiguration
  • Hosts generate IP address automatically by
    combining link information with Interface ID
  • EUI-64
  • Privacy Extensions
  • Link information is retrieved via Router
    Solicitations (RS) or Advertisements (RA)

Router Advertisements
  • RA/RSs are a subset of Neighbor Discovery (ND)
  • All routers send RAs every 5 minutes from each
    defined link local address to FF021
  • If the Default Router field has a non-zero time
    listed, it may be used as a default router
  • RAs have a Managed Address flag if set, it
    means host must contact DHCP server to generate
    Global Unicast Addresses (Stateful configuration

Quality of Service
  • IPv4 Type of Service header field has been
    renamed Traffic Class in IPv6 with identical bit
    assignment and processing
  • IPv4 has no mechanism for recognizing data
    streams, focuses on guarantees of delivery and
    TOS field
  • IPv6 has a Flow Control header field that routers
    use to prioritize data stream processing
  • Integrated Services (RFC 1633) prioritization
    without Transport Layer data inspection
  • Requires Resource Reservation Protocol (RSVP)
    RFC 2205
  • Eliminates redundant route resolution processing
  • No standard definition of FC field values
  • Introduces a potential DOS vulnerability

Packet Header Changes
  • IPv4 has variable length packet header
  • Many fields unused
  • Use of options add to variability
  • Variability led to integrity check calculation
    processing requirement
  • Options limited in complexity
  • IPv6 has fixed length packet header
  • All fields used
  • Options are well-defined
  • No requirement for integrity check processing
  • Multiple options may be stacked

IPv6 Header (Fixed length, 40 bytes) RFC 2460
IPv6 Header Detail Flow Control
  • Defined in RFC 3697
  • Size is 20 bits (2.5 bytes)
  • A random number selected by the sending host used
    to specify a particular flow of data
  • Not fully defined yet, but has the potential to
    reduce processing latency for a flow of data,
    even if it comes from different applications
  • Routers keep track of flows and once received, do
    not have to reprocess routing information for
    additional packets in that flow

IPv6 Header Detail Next Header
  • Size is 1 byte
  • Was called Protocol Type field in v4
  • Specifies what type of header is coming next in
    the packet (TCP/UDP/ICMPv6, etc)
  • If extension headers are used, the type of
    extension header is listed here
  • Common values 6 (TCP), 17 (UDP), 58 (ICMP6)

IPv6 Extension Headers
Extension Headers Intermediate Nodes
  • Hop-by-Hop Options Header
  • Jumbo Payload option
  • Router Alert option Router must process the
  • Destination Options header
  • Used by intermediate nodes when Routing header is
  • Routing header
  • Used for source routing and MobileIP

Extension Headers Destination Node
  • Fragment header
  • Used only by the source and destination nodes
  • IPSec specific headers
  • Authentication header (AH)
  • Encapsulating Security Payload (ESP) header
  • Destination Options header
  • Used only by destination node when Routing Header
    is not present
  • Used by MobileIP

IPv4 Fragmentation Control
  • Maximum Transmission Unit (MTU) defines the
    largest amount of data in octets that a device
    can send or forward in a single datagram
  • Path MTU (PMTU) is the smallest MTU of all the
    devices between a source and destination host
  • IPv4 has no PMTU discovery mechanism and sends
    packets at the size defined in the source host
  • An IPv4 intermediate node receiving a packet
    larger than the nodes MTU divides a packet into
    several smaller packets before forwarding the
    new, smaller packets
  • This introduces latency and increased traffic
    into the network

IPv6 Fragmentation Control
  • Before sending a packet, IPv6 sends a test packet
    sized to the source hosts pre-defined MTU to the
  • IPv6 listens for ICMP Packet too large messages
    and, if one is received, sends progressively
    smaller packets until a Packet too large
    message is not returned
  • IPv6 resizes the real packets to match the
    discovered PMTU
  • IPv6 requires ICMPv6 to pass thru firewalls

IPSec for IPv6
  • Mandatory inclusion in implementation
  • Three User Options
  • No Use
  • Gateway-Gateway (Available in IPv4)
  • Peer-Peer
  • Use Requires a Security Association
  • IKE RFC 2409
  • PKI/PKM (static keying is possible but
  • Two Modes
  • Transport (Peer-Peer)
  • Tunnel (VPN Gateway-Gateway)
  • Modes can be combined
  • Two Header Options
  • Authenticated Header (AH)
  • Encapsulating Security Payload (ESP)
  • Options can be combined

IPSec for IPv6
  • Authentication Header (AH)
  • RFC 2402
  • Whole packet integrity
  • Source authentication
  • Replay protection
  • Does NOT Encrypt, Uses Checksum
  • Does NOT provide Confidentiality

IPSec for IPv6
  • Encapsulating Security Payload (ESP)
  • RFC 2406)
  • Confidentiality
  • Integrity of the Encapsulated Packet
  • Authentication of the source
  • Anti-replay protection
  • Encrypts
  • Has more limited integrity check than AH
  • Encapsulating Packet is NOT protected

  • RFC 3315
  • Totally rewritten protocol
  • Required for Managed Address systems
  • Stateful Configuration
  • Automatic Address Assignment

  • Many benefits
  • Uses multicast instead of broadcast
  • Verifies that client is on-link (only supplies
    addresses from link-local addresses)
  • Relay agent is simplified since it doesnt need a
    list of DHCPv6 servers just sends to
    All-DHCP-servers address
  • Server can push an update when changes occur
  • Address Lease Lifetime is infinite when
    changes occur, they are pushed less traffic

Neighbor Discovery (ND) Protocol
  • Neighbor Discovery has two main subsets
  • Router Solicitation/Router Advertisement (RS/RA)
    to communicate with Routers
  • Neighbor Solicitation/Neighbor Advertisements
    (NS/NA) to communicate with hosts on link
  • The ultimate job of ND is to allow a node that
    knows an IPv6 address to determine the MAC
    address of the on-link recipient node
  • Very similar to ARP in IPv4, but uses multicast
    rather than broadcast

Why Neighbor Discovery?
  • Doesnt an IPv6 address advertise the MAC
  • No, it advertises the EUI-64 address, from which
    one can determine the MAC address
  • The EUI-64 isnt guaranteed to be accurate
  • It could have been randomly entered by the node
  • It could be randomly changing to protect privacy
  • The Layer 2 might not require MAC addresses
    (Frame Relay)
  • Therefore ND is always performed (unless already
  • Next slide explains IEEE EUI-64 MAC-64

EUI-64 IEEE Extended Unique Identifier64 bits
  • To facilitate the creation of globally unique
    node addresses using the network adapters Media
    Access Code (MAC) number, the IEEE established 2
    new standards EUI-64 and MAC-64.
  • Both MAC-64 and EUI-64 split the current EUI-48
    MAC-48 bit numbers into two 24-bit sections and
    then insert either FFFF (MAC-64) or FFFE (EUI-64)
    between the two sections
  • MAC-64 is meant to be used with network adapters,
    but the IPv6 specification writers used the
    EUI-64 standard instead

Solicited Node Multicast Address (SNMA)
  • SNMA is used to avoid duplicate IPv6 addresses
  • Created by adding FF (last 24 bits of Interface
    ID) onto FF021
  • Clients IPv6 address is 3001B00012126BFFFE3
  • Take the last 24 bits 3001B00012126BFFFE3A9
  • Prepend FF onto 3A9E9A
  • Append the result to the SNMA Prefix
  • Host listens on the SNMA corresponding to each
    assigned IPv6 address

Duplicate Address Detection (DAD)
  • As a function of ND, when a node generates (or
    receives) a IPv6 address, it automatically sends
    a NS packet to the SNMA that it is configuring
  • If a NA is received, node knows that address is
    in use and address is not used

Secure Neighbor Discovery (SeND)
  • Requires each node to have a trusted router
    certificate list
  • List different for each network segment
  • Uses Cryptographically Generated Addresses (CGA)
    (RFC 3972) to verify neighbors address ownership
  • Solves router trust security problems in IPv6
    Neighbor Discovery node address configuration
  • No IPv6 automatic method for creating or
    updating host and router certificate lists

  • In IPv4, the Internet Control Messaging Protocol
    (ICMP) was used for some utilities such as ping
    and tracert
  • Many organizations block in/out ICMP at the
  • In IPv6, Neighbor Discovery utilizes ICMPv6, and
    ND is mandatory for delivering packets
  • Path MTU discovery is ICMPv6 based
  • Therefore, ICMPv6 is mandatory in IPv6 and
    cannot be shut off completely at the firewall

  • Same functionality as DNS in IPv4
  • IPv6 uses AAAA records, IPv4 uses A
  • DNS queries return AAAA before A records
  • Some implementations will not return an IPv4
    address if an IPv6 address exists for the host
  • DNS server with faked IPv6 record for IPv4-only
    box will refer all traffic to IPv6 site
  • DNS Server discovery mechanisms still a work in

  • Present in IPv4 (RFC 3344), difficult to use
  • MobileIPv4
  • Mobile Node
  • Home Agent
  • Foreign Agent
  • UDP-based
  • Home Agent-(Server) centric

  • Visited networks must open their firewalls to
    special IPv6 packets
  • IPv6 Modes
  • Bi-directional Tunneling (Home Agent centric)
  • Route Optimization (Peer-to-Peer)
  • You can do Binding Updates with any correspondent
    to establish a direct path, but ONLY after
    establishing a security association with the home
    agent or correspondent.

  • Do not confuse MobileIP with Mobile
    Telephony, which concerns ISO Layers 1 2
  • MobileIP is ISO Layer 3
  • Requires a functioning Layer 1 2 network
  • Requires a way to establish security associations

Key Risk Considerations
  • Each network layer has characteristic types of
  • Internet Protocol is an address management and
    traffic delivery protocol suite
  • Characteristic attacks and activities at the IP
    level are Address Manipulation, Denials of
    Service, and supporting activities
    (reconnaissance, etc.)
  • Some attacks utilize upper layer protocols that
    support IP functionality (ICMP, TCP, UDP, etc.)
  • Almost all IPv6 security enhancements require a
    way to establish a security association (PKI?)
    (SeND, IPSec, etc.)

Key Considerations
  • IPv6 address management suite
  • Neighbor Discovery / Router Identification
  • Autoconfiguration
  • Domain Name Service
  • Dynamic Host Control Protocol
  • ICMP
  • Packet Header Changes
  • Supporting Activities

Neighbor Discovery
  • Key concerns
  • Neighbor Solicitations / Advisories
  • Router Solicitations / Advisories
  • ICMP messages
  • Secure ND requires trust lists
  • IPv6 IPv4 (NDAC ARP, etc.)
  • Attacks
  • DoS
  • Redirects
  • Configuration Attacks

Neighbor Discovery
  • Neighbor Solicitation and Advertisement (NS/NA)
  • N3 sends an NS or NA with N1, N2, or R1 addresses
    and N3 link-layer address.
  • Traffic goes to N3 instead of valid neighbors.

Neighbor Discovery
  • Fake on-link Prefix
  • N3 executes NA/NS Spoofing
  • N3 sends RA with invalid prefix identified as
  • Off-link traffic to the prefix is either denied
    or sent to N3

Neighbor Discovery
  • Neighbor Unreachability Detection (NUD) Denial of
  • N3 sends NA responding to NUD NS messages of all
    or some of others on network
  • NUDed nodes are now considered unreachable by
    other nodes, who cease sending

Neighbor Discovery
  • Router Flood
  • N3 sends randomly addressed packets
  • R1 sends NS messages that are never answered

Neighbor Discovery
  • Default Router Disabling
  • N3 sends RA with R1 address and a lifetime of
  • R1 is dropped as the default router by other nodes

Neighbor Discovery
  • Router/DHCPv6 Masquerade
  • N3 sends RA with a DHCPv6 configuration that
    points to a DHCPv6 server running on N3
  • Nodes obtain addressing information from N3

Neighbor Discovery
  • Default Router Masquerade
  • N3 sends RA as Default Router
  • Other nodes start sending traffic to N3
  • N3 becomes Man in the middle.
  • N3 can also DoS net by sending RA with an invalid
    network renumbering scheme

Neighbor Discovery
  • Duplicate Address Detection (DAD) Denial of
  • N3 responds to every DAD NS message by claiming
    to already have that address
  • Nodes are never able to configure an address

Neighbor Discovery
  • Prefix Spoofing
  • N3 sends RA with invalid network prefix for
  • Autoconfigured nodes send traffic with invalid
  • Nodes never receive misdirected response traffic

Neighbor Discovery
  • Prefix Flooding
  • N3 sends an RA flood with randomly selected
    invalid prefixes
  • Nodes eventually drop valid prefixes

Neighbor Discovery
  • ICMP Redirect
  • N3 sends R1-spoofed ICMP redirect message
  • Nodes send traffic to N3

Neighbor Discovery
  • NDAC uses Multicast
  • IPSec uses IKE
  • IKE has no mechanism for a group key
  • IKE does not support Multicast Security
  • IPSec does not easily support Multicast

  • Well-known addresses
  • EUI-64 creation
  • Privacy extensions (Randomization)

  • Well known multicast addresses
  • All routers at FF052
  • All DHCP servers at FF0513
  • All nodes at FF021
  • Human pattern issues remain (pattern in choice of
    key server addresses)

  • EUI-64 address creation
  • Exposes Layer 2 address
  • Privacy Issues
  • Privacy extensions (Randomization)
  • Loss of tracking ability

Domain Name Service
  • Default Action with AAAA vs A records
  • Public servers still public
  • DNSv6 attacks still similar to IPv4 (Zone
    Transfers, dynamic DNS, etc.)

  • ICMP message control requirements more granular
  • ICMP attacks can reach layers above IP
  • IPSec/IKE does not secure ICMP

Packet Header Changes
  • Fragmentation attacks still possible
  • Flow Control field manipulation can cause router
    overflow conditions
  • Header chaining can create overflow conditions

Supporting Activities
  • Reconnaissance
  • More difficult, not impossible
  • Minus for both attackers and vulnerability
  • Source routing still available for Man-in-Middle
  • SYNFloods and other DoS/DDoS still available for
    complex or Mitnick-type attacks
  • Smurf may still be possible using ICMP Packet too
    large and Parameter problem messages

Technology Support and Transition Strategy
  • There are three pieces to the IPv6 transition
  • Infrastructure transition
  • Host transition
  • Application transition
  • Coexistence during transition
  • The transition from IPv4 to IPv6 will take years
  • Some hosts will use IPv4 indefinitely
  • Transition is the long term goal, coexistence in
    the interim

Infrastructure Transition
  • There are two main ways of providing IPv6
    connectivity to your users
  • Upgrade all layer 3 devices to support IPv6 and
    ensure routing tables reflect new IPv6 routes
    this is the ultimate goal
  • Use a transition technology to provide IPv6
    connectivity to users in the absence of A.

  • Intra-Site Automatic Tunnel Addressing Protocol
  • Provides unicast IPv6 connectivity between IPv6
    hosts across a IPv4 intranet
  • Can use private IPv4 addresses
  • Prefix FE8000000000000000005EFE ends with
    the IPv4 address in hex form
  • One dual stack ISATAP router per site relays data
  • Benefit allows scoped deployment of IPv6
    services across without upgrading infrastructure

  • Similar to ISATAP, but requires a public IPv4

Tunnel Broker
  • Both ISATAP and 6to4 provide access to IPv6
    resources based on the IPv4 address
  • An unauthorized user could change their IP
    address and gain access to IPv6 services
  • Tunnel Brokers add an additional layer of
    authentication into the process by leveraging a
    IAS server
  • This can be especially helpful for externally
    facing 6to4 relays

  • ISATAP and 6to4 rely on a translation server in
    the local subnet
  • Home users will not have this option, and they
    are behind a NAT
  • Teredo was designed to allow home users access to
    IPv6 services by tunneling IPv6 through an IPv4
  • Microsoft does not recommend the use of Teredo in
    the Enterprise

Routing Transition Technologies
  • ISATAP or 6to4 provides connectivity between dual
    stacked and native v6 clients within your
  • IF you choose to install an ISATAP/6to4 router
    or enable BGP/OSPF IPv6 routing, then IPv6 will
    be routed into/out of your network
  • This is nothing different from IPv4

Host Transition
  • Ideal Transition Stages
  • Native IPv4
  • Dual Stack or Dual IP
  • Native IPv6
  • Dual stack will be preferred for many years
  • Very few IPv6 application issues on
    dual-stack/dual IP machines
  • Dual stack gives you the advantages of IPv6
    without requiring that every application be fully
  • Microsoft Vista is NOT dual-stack!

Application Transition
  • Wouldnt be necessary in a perfect world.
  • Maintains operation for older software, leverages
    power of v6 for new software
  • Software with embedded IPv4 addresses can operate
    without alteration in a dual stack environment
  • New or upgraded software should rigorously
    enforce OSI layer separation no embedded
    addresses or URLs

Technical Transition Criteria
  • Existing IPv4 hosts can be upgraded at any time
    independent of the upgrade of other hosts or
  • New hosts using only IPv6 can be added at any
    time without dependencies on other hosts or
    routing infrastructure
  • Existing IPv4 hosts with IPv6 installed can
    continue to use their IPv4 address and do not
    need additional addresses
  • Little preparation is needed to upgrade existing
    IPv4 nodes to IPv6 or to deploy new IPv6 nodes

Regulatory Environment
  • Non-technical environment doesnt change
  • For federal government, FISMA, NIST SP 800-53,
    etc. dont go away
  • Legal system definitions and requirements will
    have a significant impact on IPv6 technical

Some Security Practices Must Change
  • Protecting system boundaries becomes more
  • Network Address Translation (NAT) may gradually
  • IPv6 subnet size makes net scanning more
    difficult for both protector and attacker
  • Firewalls border and personal will flourish
  • Host IDS will become more important
  • Combination security devices may become more
  • Firewalls must perform very granular control of

IPv6 Security
  • Ask a lot of people about security in IPv6 and
    youll hear one thing IPsec
  • IPsec is important, but there is more to Security
    than a single protocol
  • The most important thing to do is test
  • IRS IPv6 transition should be lab tested

Work, Work, Work!
  • Firewall rules will need to be redone from
  • Broadcasts may be gone, but there are many new
    multicasts to be filtered
  • Protocol types are more important than ever
  • Implement Microsoft Active Directory based Server
    and Domain Isolation
  • Implement ingress filtering of packets with IPv6
    multicast source addresses
  • Many of the security recommendations of IPv4 are
    still in IPv6

Transition Security Recommendations
  • General Principles
  • Security Tools
  • Windows Domain Management
  • Tunneling
  • Flow Control
  • IPSec
  • MobileIP
  • Applications
  • Databases

General Considerations
  • IPv6 is a Work In Progress. Vulnerabilities,
    attack vectors, and security requirements will
    change as the protocol suite is further defined.
  • An IPv6 feature or improvement may not be
    relevant to your current or future business
    needs or in a federal environment.
  • As a general goal, IPv6 transition should not
    cause a redefinition of the logical security
    boundaries of previously certified and accredited
    (CA) systems.
  • Any IPv6 capabilities that differ from IPv4
    should be used only in response to clearly stated
    business requirements.
  • Realizing the full benefits of IPSec and SEND
    will require a previous installation of both PKI
    and MS Active Directory.

General Considerations
  • Security costs will increase due to the need to
    secure two network access protocols and the
    interactions between them
  • Technology Refresh purchase schedules may
    result in IPv6-capable systems being procured
    out of phase with same-network IPv6-capable
    security devices. Interior IPv6 capabilities
    should not be implemented without adequate
    traffic control and security by IPv6-capable
    network and perimeter control and security
  • The possibility of U-Turn attacks must be
    considered when opening internal to external

Security Tools
  • Routing devices (routers, firewalls, etc.) should
    deny passage of any externally-generated IPv6
    traffic that uses User Datagram Protocol (UDP) to
    bypass firewalls or other security tools.
  • Intrusion detection or prevention systems
    (IDS/IPS) should have the ability to perform
    analysis of tunneled IPv6 traffic without regard
    to the number of tunnel layers.
  • IDS/IPS should have the ability to analyze packet
    headers that exceed 512 octets.
  • Firewalls should have the ability to analyze both
    IPv4 and IPv6 ICMP traffic and to permit or deny
    access to such traffic based on type and message

Windows Domain Management
  • Windows Active Directory should be implemented to
    support Domain and Server Isolation.
  • All Domains and Servers should be isolated IAW
    Microsoft recommendations.
  • Active Directory should be combined with PKI

  • No automatic tunnels.
  • No tunnels based on UDP (e.g., Toredo).

Flow Control
  • Devices that respond to Flow Control in any
    fashion should be thoroughly tested for response
    to out-of-bound conditions.
  • Device is meant to refer to hardware or
    software or any combination thereof that works as
    a logical machine.

  • IPSec should be implemented in a G2G mode that
    honors current CA logical system boundaries
    except (potentially) in the following cases.
  • Where considerations of data confidentiality on
    untrusted networks require end-to-end IPSec
  • Where IPSec communication is between member
    servers of the Trusted Computer Base (TCB).
  • IPSec Security Associations required for P2P use
    IKE. P2P mode is best served in a PKI
  • Irrespective of IPSec mode implementation, all
    MS-based systems should be placed in isolated
  • Full use of IPSec requires implementation of

  • Visited networks must open their firewalls to
    special IPv6 packets
  • IPv6 in IPv6 packets
  • IPv6 packets with mobility headers
  • IPv6 packets with home address destination option
  • ICMPv6 mobility packets
  • IPv6 packets with routing headers

  • Ideally, applications should have no awareness of
    IP layer protocols.
  • Applications with a network layer component
    should be tested for compatibility with IPv4,
    IPv6, and/or whichever 4to6 and 6to4 tunneling
    mechanisms are implemented.
  • Applications that capture IP addresses should
    correctly process input of the various legal
    address format permutations and store and display
    such addresses in an enterprise-wide standard
  • Applications with embedded IPv4 addresses may
    have to be recoded depending on any network
    renumbering during the transition.
  • Note There is no current standard data field
    description for IPvX addresses.

  • Databases containing network layer addresses
    should be capable of storing both IPv4 and IPv6
    addresses in an enterprise-wide standard format.
  • Network-capable DBS should be tested for
    compatibility with IPv4, IPv6, and/or whichever
    4to6 and 6to4 tunneling mechanisms are
    implemented by the IRS.

End of Presentation
  • Questions?
  • Thanx for your attention and time.

  • This slide purposely left blank.

Extra Slides
  • Following slides are examples of some of the
    items covered in the main presentation.

Features of Network Layer Protocols
  • Logical Addressing
  • IPv6 Address Space and Syntax
  • IPv6 Address Types and Uses
  • IPv6 Interface Address Configuration
  • Route Discovery
  • Quality of Service
  • Packet Header Structures
  • Fragmentation Methods
  • Supporting Protocols

Aggregatable Global Unicast Addresses (RFC 3513)
  • Refers to the ability to collapse or aggregate
    these addresses in a routing table
  • Used for
  • Top-Level Aggregation ID (TLA ID)
  • Next-Level Aggregation ID (NLA ID)
  • Site-Level Aggregation ID (SLA ID) (deprecated)
  • Interface ID

Aggregating The /48
  • Address scope is the entire IPv6 Internet
  • Equivalent to public IPv4 addresses
  • Known as a /48 since 48 bits denote the routing
  • This is the standard (smallest) IANA allocation
  • Permits 65,532 subnets

Local-Use Unicast Addresses
  • Link-local Unicast
  • Used between on-link neighbors
  • Equivalent to IPv4 APIPA addresses
  • Single subnet, Routers will not forward
  • Neighbor Discovery Autoconfiguration (NDAC)
  • Link-Local Unicast Address Format
  • Prefix is 1111 1110 10 or FE80/64
  • Site-local addresses (deprecated)
  • Used between nodes in the same site

Site-Local Unicast
  • Address scope is a single site
  • Equivalent to private IPv4 addresses (RFC 1918)
  • Prefix Format 1111 1110 11
  • FEC0/10 prefix for site
  • Used for local site only
  • Deprecated, but may be seen

Unique Local Addresses (RFC 4193)
  • Private to an organization, yet unique across all
    of the sites of the organization
  • Depends on Router Filtering to maintain locality
  • FD00/8 prefix
  • Replacement for site-local addresses
  • Global scope within the site, no router zone ID

Special IPv6 Addresses
  • Unspecified address (new thing!)
  • 00000000 or
  • Loopback address
  • 00000001 or 1
  • DNS server is normally at
  • FEC0000FFFF1
  • FEC0000FFFF2, or
  • FEC0000FFFF3

Compatibility Addresses
  • Used to create tunneling or IPv4-derived IPv6
  • IPv4-compatible address 000000w.x.y.z or
  • IPv4-mapped address 00000FFFFw.x.y.z or
  • 6over4 address Interface ID of WWXXYYZZ
  • 6to4 address Prefix of 2002WWXXYYZZ/48
  • ISATAP address Interface ID of 05EFEw.x.y.z

NSAP Addresses (RFC 1888)
  • NSAP or Network Service Access Point is an OSI IP
    (not IPv4) addressing scheme which may become
    popular in the future, so was made fully
    compatible with IPv6
  • Currently unused

Multicast Addresses
  • Replaces IPv4 broadcast addressing
  • First byte is always FF
  • Lifetime (4 bits) 0 if permanent, 1 if temporary
  • Scope (4 bits) 2 link, 5 site, 8
    organization, E global
  • Some IANA defined multicast (group) addresses
  • FF021 (All nodes on the link)
  • FF022 (All routers on the link)
  • FF0513 (All DHCP servers in the site)

Anycast Address
  • Used to send a packet to a group of hosts and the
    closest host will respond
  • A Unicast address assigned to more than one
  • Last Hop Routers are configured with a full
    128-bit route
  • Routers must join the All routers on link
    Anycast group
  • Now a host can send a packet to discover the
    closest available Default Gateway
  • Can also be used for clustering server solutions
  • Anycast still undergoing definition

EUI-64 Example
  • Host has a MAC-48 address of 00-AA-00-3F-2A-1C
  • 1. Convert MAC address to EUI-64 format by
    inserting Hex FF FE between the Manufacturers ID
    and the Adapter Serial Number
  • 00-AA-00-FF-FE-3F-2A-1C
  • 2. Complement the 7th bit of first byte
  • The first byte in binary form is 00000000. When
    the seventh bit is complemented, it becomes
    00000010 (0x02).
  • 02-AA-00-FF-FE-3F-2A-1C
  • 3. Convert to colon hexadecimal notation and
    suppress leading zeros
  • Link-local address for node with the MAC address
    of 00-AA-00-3F-2A-1C is FE802AAFFFE3F2A1C

EUI-64 Privacy Extensions
  • Since the EUI-64/MAC address doesnt change,
    there are privacy concerns
  • RFC 3041 Privacy Extensions defines how the
    Interface ID can be randomly generated and
    changed often to protect privacy
  • Leverages preferred and valid lifetimes - 24
    hours preferred, 6 days valid
  • Privacy Extensions make internal tracking and
    scanning more difficult

Router Solicitations
  • When a host boots, it cannot wait for 5 minutes
    for configuration data
  • Host will send a Router Solicitation (RS) to
    FF022 (All-routers-on-link)

Boot Sequence Address Configuration
  • Host generates a link-local address using
    Local-Link prefix Interface ID
  • Host checks for address collision (Duplicate
    Address Detection)
  • Host sends Router Solicitation to FF022
  • Router sends Router Advertisement
  • If RA Managed Address field1, host contacts DHCP
    for Global Unicast address (FF0212 or
    FF0215 if no response)
  • If RA Managed Address field 0, host combines
    link prefix with Interface ID to create Global
    Unicast Address

  • RFC 3775
  • Components
  • Mobile Node
  • Home Agent (Transfer agent)
  • Home Address (HA) (Permanent Address)
  • Care-of-Address (CoA) (Hosting Net Address)
  • uses Packet Extension Headers
  • Can be P2P with route optimization