IDRP Prototype Implementation

Participants

• Yakov Rekhter
  • IBM Research
• Rob Coltun
  • RainbowBridge Communications
• David Jacobson
  • IBM Network Routing Systems

Prototype Implementation

• Standalone IDRP
• Integrated IP and ISO Routing
• Runs over IP or CLNP
  • CLNP requires some completion of interfaces and testing
• Loosely Coupled To GateD
• Functions
  • Basic Transport
  • Empty RIB-Att
  • Confederations
  • Policy
  • Aggregation

Policy

• Generally Follows ISO 10747 Annex.
• Three Global Lists:
  • Preference.
  • Aggregation.
  • Distribution.
• Each Statement Of Form:
  • TEMPLATE = ACTION.
• Action Performed For First Match.

Template Components

• NLRI.
• RD Path Regular Expression.
• Attribute Condition:
  • Attribute Presence.
  • Attribute Value.
• BIS:
  • Update Source For Preference.
  • Update Target For Distribution.

Actions

• Preference:
  • Calculation of Arithmetic Expression:
    • Attribute Values.
    • Constants.
• Aggregation:
  • Eligible To Be Aggregate Component.
  • Type Of Aggregate:
    • Only Manual Supported.
  • Target BIS For Aggregate.
• Distribution:
  • Eligible For Update.
  • Modifications Of Attributes:
    • Multi-Exit Discriminator.
    • Next Hop.
    • Dist List Include.
    • Dist List Exclude.

Aggregation

• Template Selects Components:
  • One Aggregate Per Statement.
  • Instantiation Requires:
    • All Components Consistent With Aggregate.
• Template Specifies A Single Address Prefix:
  • Must Subsume Component NLRI.
  • Default Instantiation Requires:
    • One Component Present.
  • Must NLRI List:
    • Can Require More Components.
  • Component And Aggregate Can Have Same NLRI.
• Aggregate Distribution:
  • BIS List On Aggregation Statement:
    • Targets For Aggregate.
    • Other BIS May Get Components.
    • Default:
      • All BIS May Get Aggregate.
      • BIS Not Eligible For Aggregate:
        • Get Nothing.
  • Distribution Policy:
    • Same Actions As For A Component:
      • Determine Targets For Update.
      • Modify Attributes.

Confederations

• For RD Path Processing In A Node:
  • All Have Entrys For The Same Confederations:
    • After Adding Entered Confederations.
    • Before Converting Exited Confederations.
• Basic Confederation Processing Decision:
  • Are Some Confederations Overlapped?
  • Are All Confederations Nested?
• Always One Choice:
  • Can Be Determined From Local Configuration.
• Can Also Predetermine Cannonical Ordering.

Simulation Testing

• Multiple IDRP Instances In One Configuration
• Simulation Routes Between Instances
• Can Test Everything Above Kernel Interface
• Advantages:
  • Minimize Equipment Requirements And Setup Time
  • Easily Recreate Problems Exactly
  • Can Generate Complex Configurations
    • 12 Node Networks Used For Aggregation Tests
  • Can Add Stress
    • Random 25% Frame Loss

Test Network

Diagram (PostScript - 14539 bytes) Of Test Network

Test Configuration

• Five 6611 Routers
• Four Routing Domains
• Three Overlapping Confederations

Diagram (PostScript - 14008 bytes) Of Logical Test Network Structure

Issues With Standard

• Section 7.18.2.1 Route Aggregation:
  • Some Constraints Don't Make Sense:
    • Multi-Exit Discriminator Must Match.
    • Next Hop Match Must Match:
      • Only Makes Sense For Route Server.
• Section 7.7.5 Flow Control:
  • Problem With Lost Acknowledgement Keepalive:
    • Risk Exceeding Transmit Retry's.
    • Solution For Update Ack's:
      • New Keepalive For Duplicate Update.
    • Also Case Of ACK Of Window Opening Keepalive.