Administrator Guide

Command
History
Version Description
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.
Z9000
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
9.7(0.0) Introduced on the S6000–ON.
9.0.2.0 Introduced on the S6000.
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.
In the event of an enfore-first-as check failure, the existing BGP session is flapped.
Related
Commands
show ip bgp neighbors — views the information the BGP neighbors exchange.
show ip protocols — views information on routing protocols.
Border Gateway Protocol 283