D-Link xStack Reference Manual page 185

xStack® DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch CLI Reference Guide
When the setting is enabled, any updates received from an external neighbor, that does not have
the neighbor's configured Autonomous System (AS) at the beginning of the AS_PATH in the
received update, will be denied. Enabling this feature adds to the security of the BGP network by
not allowing traffic from unauthorized systems.
Format
config bgp enforce_first_as [enable | disable]
Parameters
enable - Enables the enforce first AS setting.
disable - Disables the enforce first AS setting. The default setting is disabled.
Restrictions
Only Administrator, Operator and Power-User level users can issue this command. (EI Mode Only
Command)
Example
To enable the BGP process's enforce_first_as ability:
DGS-3620-28SC:admin#
Command: config bgp enforce_first_as enable
Success
DGS-3620-28SC:admin#
13-8 create bgp aggregate_address
Description
This command is used to create an aggregate entry in the Border Gateway Protocol (BGP)
database.
Using the aggregate_address command with no keywords will create an aggregate entry in the
BGP routing table, if any more specific BGP routes are available that fall within the specified range.
The aggregate route will be advertised as coming from your Autonomous System and will have the
atomic aggregate attribute set to indicate that information might be missing. That is, the original AS
path associated with more specific routes will be lost. The atomic aggregate attribute is set unless
you specify the as_set keyword.
Using the as_set keyword will create an aggregate entry, but the path advertised for this route will
include an AS set consisting of all AS that are contained in all paths that are being summarized.
Do not use continually withdrawn and updated as autonomous system path reachability
information for the summarized routes changes.
Using the summary_only keyword will create an aggregate route but suppresses advertisements of
more specific routes to all neighbors. If you want to suppress only advertisements to certain
neighbors, you may use the neighbor prefix_list command.
config bgp enforce_first_as enable
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