What is the difference between routing and forwarding? Routing - - PowerPoint PPT Presentation

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Feb 14, 2023 448 likes •513 views

Routing What is the difference between routing and forwarding? Routing protocols: Implemented distributed algorithms (scalability) Routers should have mutually consistent view of the network. Can be classified into: Intradomain

SLIDE 1

Routing What is the difference between routing and forwarding? Routing protocols:

Implemented distributed algorithms (scalability) Routers should have mutually consistent view of the network. Can be classified into:

– Intradomain versus interdomain routing protocols. – Distance vector versus link state routing protocols.

UTD, CS 6390 Ravi Prakash 38

SLIDE 2

RIP: Distance Vector Protocol

Employs Bellman-Ford algorithm. Meant for introdomain routing. Maximum supported network diameter = 16. Widely deployed: not going to disappear soon. Latest version: RIP-2.

UTD, CS 6390 Ravi Prakash 39

SLIDE 3

RIP (contd.)

UDP-based protocol. RIP port for messaging: 520. Periodic updates at 30-second intervals. Each update entry = 20 bytes. Between 1 - 25 entries per update. 180-second timer to detect link breaks.

UTD, CS 6390 Ravi Prakash 40

SLIDE 4

Problems with RIP Count-to-infinity (16): results in slow convergence. Solution:

Split horizon: do not advertise destination information to node

from which the information is learned.

Poison reverse: advertise infinite cost, instead of omitting the

advertisement, for that destination.

Triggered updates: for fast convergence.

– Guard against excessive updates. – Bundle multiple updates using 1-5 second timer. Split horizon is required, while poison reverse is optional.

UTD, CS 6390 Ravi Prakash 41

SLIDE 5

Authentication in RIP

Supported in RIP-2. If present, occupies first RIP entry (20 bytes). Authentication header contains 16-octet plain text password.