Monitoring BGP Routes with Inconsistent AS Paths

Purpose

Display information about routes that have inconsistent AS paths. Report whether the indirect next hop of a route is unreachable; if not, display the IGP cost to the indirect next hop.

The show ip bgp inconsistent-as and show bgp ipv6 inconsistent-as commands display similar information.

Action

To display information about routes that have inconsistent AS paths:

host1#show ip bgp inconsistent-as
Local BGP identifier 192.168.1.10, local AS 123
  0 routes (0 bytes used), 0 distinct destinations (0 bytes used)
  0 routes selected for route table installation
  0 path attribute entries (0 bytes used)

Status codes: > best, * invalid, s suppressed, d dampened, r rejected

  Prefix             Next-hop         MED LocPrf Weight AS-path
> 4.0.0.0/8          0.0.0.0            1         32768 empty
  4.0.0.0/8          192.168.1.1        0 11488     701 1

Meaning

Table 34 lists the show ip bgp inconsistent-as command output fields.

Table 34: show ip bgp inconsistent-as Output Fields

Field Name

Field Description

Local BGP identifier

BGP router ID of the local router

local AS

Local autonomous system number

routes

Total number of routes stored in the BGP routing table and amount of memory consumed by routes. If several peers have advertised a route to the same prefix, all routes are included in this count.

distinct destinations

Number of routes to unique prefixes stored in the BGP routing table. If several peers have advertised a route to the same prefix, only the best route is included in this count.

routes selected for route table installation

Number of routes in the BGP routing table that have been inserted into the IP routing table

path attribute entries

Number of distinct path attributes stored in BGP's internal path attributes table. If BGP receives two routes for different prefixes but with identical path attributes, BGP will create only one entry in its internal path attribute table and share it between the two routes to conserve memory.

Prefix

Prefix for the routing table entry

Next hop

IP address of the next hop

MED

Multiexit discriminator for the route

LocPrf

Local preference for the route

Weight

Assigned path weight

Origin

Origin of the route

AS-path

AS path through which this route bas been advertised

Related Documentation