Administrator Guide

Related
Commands
• show ip bgp neighbors – views the information exchanged by BGP neighbors.
• show ip protocols – views information on routing protocols.
bgp fast-external-fallover
Enable the fast external failover feature, which immediately resets the BGP session if a link to a directly connected external peer fails.
C9000 Series
Syntax
bgp fast-external-fallover
To disable fast external fallover, use the no bgp fast-external-fallover command.
Defaults Enabled.
Command Modes ROUTER BGP
Command History
Version Description
9.9(0.0) Introduced on the C9010.
9.2(1.0) Introduced on the Z9500.
8.2.1.0 Introduced on the E-Series ExaScale.
7.4.1.0 Introduced
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.
C9000 Series
Syntax
bgp four-octet-as-support
To disable fast external fallover, use the no bgp four-octet-as-support command.
Defaults Disabled (supports 2-Byte format).
Command Modes ROUTER BGP
Command History
Version Description
9.9(0.0) Introduced on the C9010.
9.2(1.0) Introduced on the Z9500.
8.2.1.0 Introduced on the E-Series ExaScale.
7.7.1.0 Introduced
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– or 2–byte identified routers. You
cannot mix them.
Where the 2-Byte format is 1-65535, the 4-Byte format is 1-4294967295. Both formats are accepted, and the
advertisements will reflect the entered format.
For more information about using the 2– or 4-Byte format, refer to the Dell Networking OS Configuration Guide.
422 Border Gateway Protocol