As-Path - Juniper JUNOS OS 10.4 - FOR EX REV 1 Manual

Complete Software Guide for Junos

as-path

Syntax
Hierarchy Level
Release Information
Description
Options
1956
®
OS for EX Series Ethernet Switches, Release 10.4
as-path <as-path> <aggregator as-number ip-address> <atomic-aggregate> <origin (egp |
igp | incomplete)>;
[edit logical-systems logical-system-name routing-instances routing-instance-name
routing-options (aggregate | generate | static) (defaults | route)],
[edit logical-systems logical-system-name routing-instances routing-instance-name
routing-options rib routing-table-name (aggregate | generate | static) (defaults | route)],
[edit logical-systems logical-system-name routing-options (aggregate | generate | static)
(defaults | route)],
[edit logical-systems logical-system-name routing-options rib routing-table-name (aggregate |
generate | static) (defaults | route)],
[edit routing-instances routing-instance-name routing-options (aggregate | generate | static)
(defaults | route)],
[edit routing-instances routing-instance-name routing-options rib routing-table-name
(aggregate | generate | static) (defaults | route)],
[edit routing-options (aggregate | generate | static) (defaults | route)],
[edit routing-options rib routing-table-name (aggregate | generate | static) (defaults | route)]
Statement introduced before Junos OS Release 7.4.
Statement introduced in Junos OS Release 9.0 for EX Series switches.
Associate BGP autonomous system (AS) path information with a static, aggregate, or
generated route.
In Junos OS Release 9.1 and later, the numeric range for the AS number is extended to
provide BGP support for 4-byte AS numbers as defined in RFC 4893, BGP Support for
Four-octet AS Number Space. RFC 4893 introduces two new optional transitive BGP
attributes, AS4_PATH and AS4_AGGREGATOR. These new attributes are used to
propagate 4-byte AS path information across BGP speakers that do not support 4-byte
AS numbers. RFC 4893 also introduces a reserved, well-known, 2-byte AS number, AS
23456. This reserved AS number is called AS_TRANS in RFC 4893. For more information,
see Configuring AS Numbers for BGP. All releases of the Junos OS support 2-byte AS
numbers.
In Junos OS Release 9.2 and later, you can also configure a 4-byte AS number using the
AS-dot notation format of two integer values joined by a period: <16-bit high-order value
in decimal>.<16-bit low-order value in decimal>. For example, the 4-byte AS number
of 65,546 in plain-number format is represented as 1.10 in the AS-dot notation format.
You can specify a value in the range from 0.0 through 65535.65535 in AS-dot notation
format.
—(Optional) Attach the BGP
aggregator
You must specify the last AS number that formed the aggregate route (encoded as
two octets) for as-number
the aggregate route for
as-path —(Optional) AS path to include with the route. It can include a combination of
individual AS path numbers and AS sets. Enclose sets in brackets ( [ ] ). The first AS
number in the path represents the AS immediately adjacent to the local AS. Each
path attribute to the aggregate route.
aggregator
, followed by the IP address of the BGP system that formed
.
in-address
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