Route Origin

The route server will mark all routes with certain BGP Communities to indicate their origin. You can use this information to determine where a certain route has been injected into the PIE Karachi switching platform. This gives you the option to filter routes learned from the route servers based on geographical location. 

Currently we tag the following information:

• Switch: Indicates at which switch a prefix has been injected into the PIE Karachi platform. We tag the corresponding edge switch of the port.
  • Example: edge01.khi1
     
• Metro: The metropolitan region corresponding to the switch
  • Example: Karachi
     
• Country: The country corresponding to the above (in M49 format)
  
  • Example:  Pakistan
     
• Continent: The continent corresponding to the above (in M49 format)
  • Example: Asia

This means that every route you will learn from the route servers will have four (additional) BGP Communities (per community class, e.g. each Standard and Large respectively) attached which indicate location information.

To avoid ambiguity about the semantics of a certain BGP Community, especially when being present multiple times, we strip all BGP Communities from the range that we use for route origin tagging on import. This is:

• Standard Communities
  • 65101:*
  • 65102:*
  • 65103:*
  • 65104:*
     
• Large Communities
  • 140307:1911:*
  • 140307:1912:*
  • 140307:1913:*
  • 140307:1914:*

Overview

Example

A prefix has the following BGP Communities attached to it:

• 65104:142
• 140307:1914:142
• 65103:586
• 140307:1913:586
• 65102:51000
• 140307:1912:47
• 65101:51175
• 140307:1911:175

From these BGP Communities you can deduce that this particular prefix has been injected in Asia (65104:142, 140307:1914:142), Pakistan (65103:586, 140307:1913:586) in metro region Karachi (65102:51000, 140307:1912:47) at edge01.khi1 (65101:51175,140307:1911:175).