3Com 10014299 Entry, an AS Path-list, Define an access list entry, Define an AS Path-list entry

		Configuring BGP 467
	Table 551 Allow the Import of Network 0.0.0.0 into the BGP
	Operation	Command
	Allow the import of network 0.0.0.0 into	default-information
	the BGP
	Disable the import of network 0.0.0.0 into	undo default-information
	the BGP
	By default, the import of network 0.0.0.0 into BGP is disabled.
Defining an Access List	This section describes the configuration of an access list, an AS path list, and a
Entry, an AS Path-list	routing policy.
Entry, a Routing Policy	Define an access list entry
	See “Access Control List” in ****need proper ref here 3Com Router Operation
	Manual (Security Configuration)******. for more details.
	Define an AS Path-list entry
	There is an AS path field in the routing information packet of the BGP protocol.
	When the BGP protocol operates with the switching routing information, the path
	of the routing information crossing the AS is recorded in this field. aspath-listis
	identified with aspath-list-number.When defining aspath-list, you can specify
	an aspath regular expression used to match the aspath field in the routing
	information. Use aspath-listto match the aspath field in the BGP routing
	information, filtering the information that does not meet the conditions. You can
	define multiple aspath-lists for one list number so that one list number represents
	a group of aspath-lists. Each AS path list is identified with numbers.
	Perform the following configurations in system view.
	Table 552 Define a BGP-related ACL Entry
	Operation	Command
	Define a BGP-related ACL entry	ip as-path acl aspath-list-number {
		permit deny } as-regular-expression
	Remove a BGP-related ACL entry	undo ip as-path acl
		aspath-list-number
	By default, no access list entry is defined.
	In the matching process, many aspath-list-numberus Boolean “OR” operation so
	that if the routing information passes one item, information is filtered by the
	as-path list identified with this list number.
	Define a routing policy
	A routing policy is an important way for BGP to implement the route strategy.
	According to the matching result of the route attribute, BGP decides on the
	operations to be applied on a route attribute. In each routing policy, there can be
	several matching rules, labeled with a serial number. When importing a route, it is
	compared to a rule by number, from small to large. When the first matched rule is
	found, the matching process is completed. If no matched rules are found, router
	reception and transmission is canceled.