Brocade Communications Systems ICX 7250 series, Руководство по настройке

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Syntax: [no] enforce-first-as
To enable this feature for a specific neighbor, enter the following command at the BGP4 configuration level.
device(config-bgp)# neighbor 10.1.1.1 enforce-first-as enable
Syntax: [no] neighbor ip-address enforce-first-as [ enable | disable ]
The ip-address value is the IP address of the neighbor.
When the first-as requirement is enabled, its status appears in the output of the show running configuration command. The optional last
keyword choice of enable or disable lets you specify whether the output of the show running configuration command includes the
configuration of the first-as requirement. This option allows the show running configuration command output to show what is actually
configured.
To enable this feature for a peer group, enter the following command at the BGP4 configuration level.
device(config-bgp)# neighbor Peergroup1 enforce-first-as enable
Syntax: [no] neighbor peer-group-name enforce-first-as [ enable | disable ]
The peer-group-name value is the name of the peer group.
When the first-as requirement is enabled, its status appears in the output of the show running configuration command. The optional last
keyword choice, that of
enable or disable , lets you specify whether the output of the show running configuration command includes the
configuration of the first-as requirement: this option helps the show running command output to show what you have actually configured.
The following example shows a running configuration with the first-as enforcement items (for global, peer group, and neighbor) in bold.
device(config)# router bgp
BGP4: Please configure 'local-as' parameter in order to enable BGP4.
device(config-bgp)# local-as 1
device(config-bgp)# enforce-first-as
device(config-bgp)# neighbor abc peer-group
device(config-bgp)# neighbor abc remote-as 2
device(config-bgp)# neighbor abc enforce-first-as disable
device(config-bgp)# neighbor 192.168.1.2 peer-group abc
device(config-bgp)# neighbor 192.168.1.2 enforce-first-as enable
Disabling or re-enabling comparison of the AS-Path length
AS-Path comparison is Step 5 in the algorithm that BGP4 uses to select the next path for a route. Comparison of the AS-Path length is
enabled by default. To disable it, enter the following command at the BGP4 configuration level of the CLI.
device(config-bgp)# as-path-ignore
Syntax: [no] as-path-ignore
This command disables comparison of the AS-Path lengths of otherwise equal paths. When you disable AS-Path length comparison, the
BGP4 algorithm shown in
How BGP4 selects a path for a route (BGP best path selection algorithm) on page 275 skips from Step 4 to
Step 6.
Enabling or disabling comparison of device IDs
Device ID comparison is Step 10 in the algorithm BGP4 uses to select the next path for a route.
NOTE
Comparison of device IDs is applicable only when BGP4 load sharing is disabled.
Optional BGP4 configuration tasks
Brocade FastIron Layer 3 Routing Configuration Guide
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