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

Monitoring BGP Routes with Inconsistent AS Paths

Purpose

Action

Meaning

Related Documentation