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Ignore Router-ID in Best-Path Calculation
You can avoid unnecessary BGP best-path transitions between external paths under certain conditions. The
bgp bestpath
router-id ignore
command reduces network disruption caused by routing and forwarding plane changes and allows for faster
convergence.
Four-Byte AS Numbers
You can use the 4-Byte (32-bit) format when configuring autonomous system numbers (ASNs).
The 4-Byte support is advertised as a new BGP capability (4-BYTE-AS) in the OPEN message. If a 4-Byte BGP speaker has sent
and received this capability from another speaker, all the messages will be 4-octet. The behavior of a 4-Byte BGP speaker is different
with the peer depending on whether the peer is a 4-Byte or 2-Byte BGP speaker.
Where the 2-Byte format is 1-65535, the 4-Byte format is 1-4294967295. Enter AS numbers using the traditional format. If the ASN
is greater than 65535, the dot format is shown when using the
show ip bgp
commands. For example, an ASN entered as
3183856184 appears in the
show
commands as 48581.51768; an ASN of 65123 is shown as 65123. To calculate the comparable dot
format for an ASN from a traditional format, use ASN/65536. ASN%65536.
Traditional
Format
DOT Format
65001
0.65501
65536
1.0
100000
1.34464
4294967295
65535.65535
When creating Confederations, all the routers in a Confederation must be either 4-Byte or 2-Byte identified routers. You cannot mix
them.
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 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.
180
Border Gateway Protocol IPv4 (BGPv4)
Содержание S4048-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 9 0 0 ...
Страница 146: ...Figure 14 BFD Three Way Handshake State Changes 146 Bidirectional Forwarding Detection BFD ...
Страница 477: ...Figure 68 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 477 ...
Страница 480: ...Figure 70 Inspecting a LAG Port on BRAVO Using the show interface Command 480 Link Aggregation Control Protocol LACP ...
Страница 481: ...Figure 71 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 481 ...
Страница 522: ...Figure 87 Configuring Interfaces for MSDP 522 Multicast Source Discovery Protocol MSDP ...
Страница 523: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 523 ...
Страница 524: ...Figure 89 Configuring PIM in Multiple Routing Domains 524 Multicast Source Discovery Protocol MSDP ...
Страница 528: ...Figure 91 MSDP Default Peer Scenario 1 528 Multicast Source Discovery Protocol MSDP ...
Страница 529: ...Figure 92 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 529 ...
Страница 530: ...Figure 93 MSDP Default Peer Scenario 3 530 Multicast Source Discovery Protocol MSDP ...
Страница 633: ...Policy based Routing PBR 633 ...
Страница 777: ...Figure 119 Single and Double Tag TPID Match Service Provider Bridging 777 ...
Страница 778: ...Figure 120 Single and Double Tag First byte TPID Match 778 Service Provider Bridging ...