Chapter 28: Bgp Commands - Extreme Networks ExtremeWare XOS Command Reference Manual

28 BGP Commands
Border Gateway Protocol (BGP) is an exterior routing protocol that was developed for use in TCP/IP
networks. The primary function of BGP is to allow different autonomous systems (ASs) to exchange
network reachability information.
An autonomous system is a set of routers that are under a single technical administration. This set of
routers uses a different routing protocol (such as OSPF) for intra-AS routing. One or more routers in the
AS are configured to be border routers, exchanging information with other border routers (in different
autonomous systems) on behalf of all of the intra-AS routers.
BGP can be used as an exterior gateway protocol (EBGP), or it can be used within an AS as an interior
gateway protocol (IBGP).
Licensing
BGP requires a Core license, at a minimum. The BGP process will not spawn without the required
license level. The MSM-1XL is shipped with an Advanced Core license and the MSM-1 is shipped with
a Core license. Other platforms can be upgraded to a Core license. See the section
in chapter 1, "ExtremeWare XOS
information about licensing.
BGP Attributes
The following BGP attributes are supported by the switch:
Origin—Defines the origin of the route. Possible values are IGP, EGP, and incomplete.
●
AS_Path—The list of ASs that are traversed for this route.
●
Next_hop—The IP address of the next hop BGP router to reach the destination listed in the NLRI
●
field.
Multi_Exist_Discriminator—Used to select a particular border router in another AS when multiple
●
border routers exist.
Local_Preference—Used to advertise this router's degree of preference to other routers within the
●
AS.
Atomic_aggregate—Indicates that the sending border router is used a route aggregate prefix in the
●
route update.
Aggregator—Identifies the BGP router AS number and IP address that performed route aggregation.
●
Community—Identifies a group of destinations that share one or more common attributes.
●
Cluster_ID—Specifies a 4 byte field used by a route reflector to recognize updates from other route
●
reflectors in the same cluster. A route can contain a sequence of CLUSTER_ID values representing
the reflection path that the route has passed.
Originator_ID—Specifies the Router_ID of the originator of the route in the local AS.
●
ExtremeWare XOS 11.3 Command Reference
Overview", in the ExtremeWare XOS 11.2 Concepts Guide for more
"Software Licensing"
1409