BGP Concepts

BGP Session

• Establish 179
• Exchange all active path routes
• Exchange incremental updates
• (Keep connection alive)
• Message types
  • OPEN
  • UPDATE
  • KEEPALIVE
  • NOTIFICATION (errors in prev, close connection)
• eBGP, iBGP

Policy Based Routing

• Path selection by multiple metrics
• Import policy to accept or reject path
• Advertise paths based on policy
• (Won’t advertise if no revenue to be made; path vector doesn’t include any customers)

Signaling: ICMP

• Used for error reporting