Dell S4048T, Configuration Manual

Page: 221 / 1277

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 default method the system uses. 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 notation, 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
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+
Dell(conf-router_bgp)# bgp asnotation asdot+
Dell(conf-router_bgp)#show conf
!
router bgp 100
bgp asnotation asdot+
Border Gateway Protocol IPv4 (BGPv4) 221