Content

| 9.6 |  | BGP Attributes |
| 9.6.14 |  | The Origin attribute |

The Origin attribute is a well-known mandatory attribute, type code 1, that indicates the origin of the routing update. BGP allows the following three types of origins:

- IGP – The prefix is internal to the originating AS.
- EGP – The prefix was learned by way of some EGP, such as BGP.
- Incomplete – The prefix was learned by some other means, probably redistribution.

BGP considers the Origin attribute in its decision making process to establish a preference ranking among multiple routes. Specifically, BGP prefers the path with the lowest origin type, where IGP is lower than EGP, and EGP is lower than Incomplete.

| Web Links Configuring BGP http://www.cisco.com/univercd/cc/td/doc/product/ software/ios122/122cgcr/fipr_c/ipcprt2/1cfbgp.htm