DGS-6604
bgp asnotation dot
CLI Reference Guide
68
bgp asnotation dot
Use this command to change the default display and regular expression match
format of BGP 4-byte AS numbers from asplain (decimal values) to dot notation.
Use the no form of the command to reset the default 4-byte autonomous system
number display and regular expression match format to asplain.
bgp asnotation dot
no bgp asnotation dot
Syntax
None
Default
BGP AS numbers are displayed using asplain (decimal value) format in screen
output, and the default format for matching 4-byte autonomous system numbers
in regular expressions is asplain.
Command Mode
Router configuration
Usage Guideline
BGP AS numbers that were allocated to companies were 2-byte numbers in the
range from 1 to 65535 as described in RFC 4271. Due to increased demand for
AS numbers, the IANA will start, in January 2009, to allocate four-byte AS
numbers in the range from 65536 to 4294967295. RFC 5396 documents three
methods of representing autonomous system numbers. BGP has implemented
the following two methods:
•
Asplain-Decima
l value notation where both 2-byte and 4-byte AS num-
bers are represented by their decimal value. For example, 65525 is a 2-
byte AS number and 65545 is a 4-byte autonomous system number.
•
Asdot-Autonomous
system dot notation where 2-byte AS numbers are
represented by their decimal value and 4-byte AS numbers are repre-
sented by a dot notation. For example, 65525 is a 2-byte autonomous
system number and 1.10 is a 4-byte AS number (this is dot notation for
the 65545 decimal number).
After the command is performed, the output is converted in order to format it. For
some of the information which is learned prior, for example:
routes
, the AS
notation format follows the previous format. Therefore, the
clear ip bgp
command on page 95
must be used to convert to the current format.
Example
This example (on the next page) shows how to configure asnotation and shows
the difference using the command
show ip bgp
:
