Administrator Guide

Command
History
Version Description
9.9(0.0) Introduced on the C9010 Series.
9.8(0.0) Introduced on the S3048–ON and S4048–ON.
9.7(0.0) Introduced on the S-Series.
Usage
Information
Configuring or un-configuring the command will bring down and bring up the BGP Route Manager, this
will result in tear down and re-establishment of all active sessions.
Link Bandwidth has to be configured on the router in order to tell it to associate Link Bandwidth with
prefixes (paths) and/or to use Link Bandwidth in BGP Multipath route selection.
This is done under BGP configuration and is supported per address family – for IPv4 and IPv6 address
families.
The configuration for a particular address family will apply across all VRFs configured.
This command must be performed on the router which is attaching link bandwidth to prefixes (typically a
border router) as well as the router which is expected to load share traffic proportional to the bandwidth
of the external links.
bgp enforce-first-as
Disable (or enable) enforce-first-as check for updates received from EBGP peers.
C9000 Series
Syntax
bgp enforce-first-as
To turn off the default, use the no bgp enforce-first-as command.
Defaults Enabled
Command Modes ROUTER BGP
Command
History
This guide is platform-specific. For command information about other platforms, refer to the relevant Dell
Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version Description
9.9(0.0) Introduced on the C9010.
9.2(1.0) Introduced on the Z9500.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.7.0 Introduced on the S4810.
7.8.1.0 Introduced on the S-Series.
7.7.1.0 Introduced on the C-Series.
7.4.1.0 Introduced.
Usage
Information
This command is enabled by default, that is for all updates received from EBGP peers, BGP ensures that
the first AS of the first AS segment is always the AS of the peer. If not, the update is dropped and a
counter is increments. Use the show ip bgp neighbors command to view the “failed enforce-first-
as check” counter.
If you disable the enforce-first-as command, it can be viewed using the show ip protocols
command.
Border Gateway Protocol 337