Netgear XCM8810 - 8800 SERIES 10-SLOT CHASSIS SWITCH ユーザーズマニュアル

Next_hop—The IP address of the next hop BGP router to reach the destination listed in 

the NLRI field.

Multi_Exit_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 has used a route aggregate 

prefix in the route update.

Aggregator—Identifies the BGP router AS number and router ID for the router that 

performed route aggregation.

AS4_Aggregator: This attribute is used by 4-byte peers when sending updates to 2-byte 

peers. This attribute carries AS-number information that can be represented only in 
4-bytes.

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.

Originator_ID—Specifies the router ID of the originator of the route in the local AS. 

Extended Community—Provides a mechanism for labeling BGP-4 update messages that 
carry information 

Multiprotocol reachable NLRI—Used to advertise a feasible BGP route for the non 

IPv4-unicast address family 

Multiprotocol unreachable NLRI—This attribute is used to withdraw multiple unfeasible 

routes from service

BGP Community Attributes

A BGP community is a group of BGP destinations that require common handling. XCM8800 
supports the following well-known BGP community attributes:

no-export

no-advertise

no-export-subconfed

Extended Community Attributes

The extended community attribute provides a mechanism to label BGP routes. It provides 
two important enhancements over the standard community attribute:

An expanded range. Extended communities are 8-bytes wide, whereas regular 

communities were only 4-bytes wide. So, this ensures that extended communities can be 
assigned for a plethora of uses, without the fear of overlap.

The addition of 'Type' field provides structure for the extended community