Case Study-Hub and Spoke MPLS VPN Network with Sites Using Same AS Numbers

Command Reference

Command	Description
Router(config-router-af)#neighbor ip-address as-override	Configures a PE router to override the AS number of a site with the AS number of a provider.
Router(config-router-af)#neighbor allowas-in number	Configures a PE router to allow readvertisement of all prefixes containing duplicate AS numbers.
Router(config-router)#neighbor peer-group-name peer-group	Creates a BGP or multiprotocol BGP peer group.
Router(config-router)#neighbor {ip-address | peer-group-name} route-map map-name {in | out}	Applies a route-map to incoming or outgoing routes.
Router(config-router-af)#neighbor ip-address route-reflector-client	To configure the router as a BGP RR and configure the specified neighbor as its client, use the neighbor route-reflector-client command in address-family or router configuration mode.
Router(config-router)#neighbor {ip-address | peer-group-name} send-community [both | standard | extended]	Specifies that a community's attribute should be sent to a BGP neighbor.
Router(config-router)#neighbor {ip-address | ipv6-address | peer-group-name} update-source interface-type interface-number	Allows BGP sessions to use any operational interface for TCP connections.
Router(config-router)#no bgp default ipv4-unicast	Disables the IPv4 unicast address-family on all neighbors.
Router(config-router)#bgp rr-group {community-list-number}	Creates a RR group and enables automatic inbound filtering for VPNv4 updates based on the allowed route target extended communities.
Router(config)#ip bgp-community new-format	Displays BGP communities in the format AA:NN.
Router (config)#ip community-list {standard-list-number | expanded-list-number [regular-expression] | {standard | expanded} community-list-name} {permit | deny} {community-number | regular-expression}	Creates a numbered or named community list for BGP and controls access to it.
Router(config)#ip extcommunity-list standard-list-number expanded-list-number {permit | deny} [regular-expression] [rt | soo extended-community-value]	Creates an extended community access-list and controls access to it.
Router(config-map)#set community {community-number [additive] | none}	Sets the BGP communities attribute.
Router(config-map)#set extcommunity {rt extended-community-value [additive] | soo extended-community-value}	Sets BGP extended-community attributes.