As4 Number Representation - Dell Z9000 Configuration Manual

Configure 4-byte AS numbers with the four-octet-support command.

AS4 Number Representation

Dell Networking OS supports multiple representations of 4-byte AS numbers: asplain, asdot+, and asdot.
NOTE: The ASDOT and ASDOT+ representations are supported only with the 4-Byte AS numbers
feature. If 4-Byte AS numbers are not implemented, only ASPLAIN representation is supported.
ASPLAIN is the method Dell Networking OS has used for all previous Dell Networking OS versions.
ASPLAIN remains the default method with Dell Networking OS. With the ASPLAIN notation, a 32-bit
binary AS number is translated into a decimal value.
• All AS numbers between 0 and 65535 are represented as a decimal number when entered in the CLI
and when displayed in the show commands output.
• AS numbers larger than 65535 are represented using ASPLAIN notation. When entered in the CLI and
when displayed in the show commands output, 65546 is represented as 65546.
ASDOT+ representation splits the full binary 4-byte AS number into two words of 16 bits separated by a
decimal point (.): <high-order 16 bit value>.<low-order 16 bit value>. Some examples are shown in the
following table.
• All AS numbers between 0 and 65535 are represented as a decimal number, when entered in the CLI
and when displayed in the show commands outputs.
• AS Numbers larger than 65535 is represented using ASDOT notation as <higher 2 bytes in
decimal>.<lower 2 bytes in decimal>. For example: AS 65546 is represented as 1.10.
ASDOT representation combines the ASPLAIN and ASDOT+ representations. AS numbers less than 65536
appear in integer format (asplain); AS numbers equal to or greater than 65536 appear in the decimal
format (asdot+). For example, the AS number 65526 appears as 65526 and the AS number 65546 appears
as 1.10.
Dynamic AS Number Notation Application
Dell Networking OS applies the ASN notation type change dynamically to the running-config statements.
When you apply or change an asnotation, the type selected is reflected immediately in the running-
configuration and the show commands (refer to the following two examples).
Example of Dynamic Changes in the Running Configuration When Using the bgp asnotation
Command
Example of the Running Configuration When AS Notation is Disabled
ASDOT
Dell(conf-router_bgp)#bgp asnotation asdot
Dell(conf-router_bgp)#show conf
!
router bgp 100
bgp asnotation asdot
bgp four-octet-as-support
neighbor 172.30.1.250 local-as 65057
<output truncated>
Dell(conf-router_bgp)#do show ip bgp
BGP table version is 24901, local router ID is 172.30.1.57
<output truncated>
ASDOT+
178
Border Gateway Protocol IPv4 (BGPv4)