Skip to main content
Sign Out

Welcome to Dell

My Account
  • Place orders quickly and easily
  • View orders and track your shipping status
  • Enjoy members-only rewards and discounts
  • Create and access a list of your products
  • Manage your Dell EMC sites, products, and product-level contacts using Company Administration.
Sign In Create an Account Dell Financial Services Premier Sign In Partner Program Sign In
Contact Us

Your Dell.com Carts

Dell EMC SmartFabric OS10 User Guide Release 10.5.1

PDF

BFD three-way handshake

A BFD session requires a three-way handshake between neighboring routers. In the following example, the handshake assumes:
  • One router is active, and the other router is passive.
  • This is the first session established on this link.
  • The default session state on both ports is Down.
  1. The active system sends a steady stream of control packets to indicate that its session state is Down until the passive system responds. These packets are sent at the desired transmit interval of the Active system. The Your Discriminator field is set to zero.
  2. When the passive system receives a control packet, it changes its session state to Init and sends a response to indicate its state change. The response includes its session ID in the My Discriminator field and the session ID of the remote system in the Your Discriminator field.
  3. The active system receives the response from the passive system and changes its session state to Up. It then sends a control packet to indicate this state change. Discriminator values exchange, and transmit intervals negotiate.
  4. The passive system receives the control packet and changes its state to Up. Both systems agree that a session is established. However, because both members must send a control packet, which requires a response, whenever there is a state change or change in a session parameter, the passive system sends a final response indicating the state change. After this, periodic control packets exchange.
BFD three-way handshake

Rate this content

Accurate
Useful
Easy to understand
Was this article helpful?
0/3000 characters
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please select whether the article was helpful or not.
  Comments cannot contain these special characters: <>()\