NATs (Network Address Translators) - Columbia University

NATs (Network Address Translators) - Columbia University

NATs (Network Address Translators) Henning Schulzrinne Dept. of Computer Science Columbia University Fall 2003 NATs Network address translation = local, LAN-specific address space translated to small number of globally routable IP addresses Motivation:

scarce address space cost: about $9k/year for up to 262,000 addresses prevent home broadband users from running servers at home security: prevent unsolicited inbound requests avoid renumbering if provider changes

most small/mid-sized LANs inherit address space from ISP Prevalence of NATs Claim: 50% of broadband users are behind NATs All Linksys/D-Link/Netgear home routers are NATs Measurement: for Quake III users, about 1725% using NAT (May/June 2001) NAT details

RFC 1631 (first description) RFC 1918 (private-use addresses) RFC 2663 RFC 2776 RFC 3022 RFC 3027 RFC 3235 RFC 3424 RFC 3489 (STUN)

NAT types All use net-10/8 (10.*.*.*) or 192.168/16 (172.16/12 also available) Address translation Address-and-port translation (NAPT) most common form today, still called NAT one external (global) IP address

Recently Viewed Presentations

  • The Changing Environment of Management

    The Changing Environment of Management

    Coping with Business Cycles. Up-and-down movement of an economy's ability to generate wealth. Predictive structure but variable timing. Cycle-Sensitive Decisions. Timing is everything. Stay ahead of the pack. ... The Changing Environment of Management
  • WSLL Annual General Meeting/ Parent Orientation March 6,

    WSLL Annual General Meeting/ Parent Orientation March 6,

    WSLL Annual General Meeting/ Parent Orientation March 6, 2017 * * * * * * * * * * * * * - Election - Board of Director Members * Ron Zabko Mike Williams Jon Anderson Steve Sopko John O'Grady...
  • Rotational Kinematics - EIU

    Rotational Kinematics - EIU

    Rotational Kinematics If the angular acceleration is constant: Thrown for a Curve To throw a curve ball, a pitcher gives the ball an initial angular speed of 157.0 rad/s. When the catcher gloves the ball 0.795 s later, its angular...
  • Macbeth Fair is foul

    Macbeth Fair is foul

    BETRAYAL OF A FRIENDAct 3, Scenes 1 - 3 . Tuesday, 13 March 2018. Act 3, Scene 1. Macbeth. Banquo. Lady Macbeth. Servant. First Murderer. Second Murderer. The. theme of deception . is key throughout the play and linked to...
  • Asepse, antisepse, sterilizace, dezinfekce, krevní transfúze

    Asepse, antisepse, sterilizace, dezinfekce, krevní transfúze

    Asepse, antisepse, sterilizace, dezinfekce, krevní transfúze Novák P. Chir. klinika FN Plzeň Historie I. Středověk - období aseptického temna " pus bonum et laudabile" Vysoká úmrtnost při chirurgických výkonech z důvodu infekčních komplikací.
  • Chapter 1

    Chapter 1

    If only two non collinear members are connected to a joint that has no external loads or reactions applied to it, then the force in both members is zero. If three members, two of which are collinear, are connected to...
  • Cholesterol metabolism:

    Cholesterol metabolism:

    This condition is known as ketoacidosis. Utilisation of ketone bodies (ketolysis) The liver cannot utilize ketone bodies because it lacks the enzyme Thiophorase or CoA transferase which is required for the activation of ketone bodies Acetoacetate and -hydroxybutyrate can be...
  • Economia Bancria e Financeira Unidade 01 A problemtica

    Economia Bancria e Financeira Unidade 01 A problemtica

    Economia Bancária e Financeira * * Economia Bancaria e Financeira lic Economia * * * * * * * * * Principio de separação de Fisher w0 VA w*O 1. com mercado de capitais (yo-Co)(1+r) Yo+C1 Y1+C1 c1 Y1 y0-I...