miércoles, 30 de octubre de 2013

Mejores practicas configuraciones Cisco - BGP Consistency Check not enabled

BGP Consistency Check not enabled




ExcepciónBGP Consistency Check not enabled
CategoriaBGP;IP routing
Tipo OSIOS
RiesgoMedio
Descripción"A BGP route inconsistency with a peer occurs when an update or withdraw is not sent to a peer, resulting in black-hole routing. BGP Consistency checker will check for inconsistencies in a configurable interval.

Once the process identifies such an inconsistency, it will report the inconsistency with a syslog message, and optionally take action if the auto-repair keyword is specified.

Three options are available:

  • Next-Hop Label Consistency Check
  • RIB-Out Consistency Check
  • Aggregation Consistency Check

Next Hop Label Consistency Check:

When two paths have the same next hop because they are advertised by the same provider edge router (PE), they should also have the same next-hop label. If the labels are different, there is an inconsistency. If the auto-repair keyword is specified, the system will send a route-refresh request.

RIB-Out Consistency Check:

If a network passes an outbound policy and is not sent, or if a network does not pass an outbound policy and is sent, there is an inconsistency. If the auto-repair keyword is specified, the system will send a route-refresh request.

Aggregation Consistency Check:

f specific routes and the aggregated route become out of sync, an inconsistency can occur. Either the error-message keyword or the auto-repair keyword will trigger aggregation reevaluation."


Acción Correctiva!
bgp consistency-checker {error-message | auto-repair} [interval minutes]
!
error-message :System to generate an error message when an inconsistency is observed.
auto-repair : System generates a syslog and also takes an action based on the inconsistency found.
interval : Range is from 5 to 1440 minutes. Interval defaults to 1440 (One Day)

Advertencia"This is applicable for IOS

  • 15.1(2)S
  • Cisco IOS XE 3.3S."