Reference Guide

The following is a list of the FTOS version history for this command.
Version 8.3.19.0 Introduced on the S4820T.
Version 8.3.11.1 Introduced on the Z9000.
Version 8.3.7.0 Introduced on the S4810.
Version 7.8.1.0 Introduced on the S-Series.
Version 7.7.1.0 Introduced on the C-Series.
Usage
Information
The bgp fast-external-fallover command appears in the show config
command output.
bgp four-octet-as-support
Enable 4-byte support for the BGP process.
Z9000
Syntax
bgp four-octet-as-support
To disable fast external failover, use the no bgp four-octet-as-support command.
Defaults Disabled (supports 2–byte format)
Command Modes ROUTER BGP
Command History
This guide is platform-specific. For command information about other platforms, refer to the
relevant FTOS Command Line Reference Guide .
The following is a list of the FTOS version history for this command.
Version 8.3.19.0 Introduced on the S4820T.
Version 8.3.11.1 Introduced on the Z9000.
Version 8.3.7.0 Introduced on the S4810.
Version 7.8.1.0 Introduced on the S-Series.
Version 7.7.1.0 Introduced on the C-Series.
Usage
Information
Routers supporting 4-byte ASNs advertise that function in the OPEN message. The behavior of
a 4-byte router is slightly different depending on whether it is speaking to a 2-byte router or a 4-
byte router.
When creating Confederations, all the routers in the Confederation must be 4 byte or 2 byte
identified routers. You cannot mix them.
Where the 2-byte format is from 1 to 65535, the 4-byte format is from 1 to 4294967295. Both
formats are accepted and the advertisements reflect the entered format.
For more information about using the 2 byte or 4-byte format, refer to the FTOS Configuration
Guide .
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