The ratio of SVD local: total routes (x) can be found using the number of SVD Local Routes and the number
of Total Routes for a given VRF. For example, in the above sample output of show cef tables location
0/1/CPU0, in the L column, the number represents the Local Routes, and in the T column number represents
Total routes in that Vrf. So ratio of L column to T column number will give the ratio for a given vrf. Again
if the ratio is not same for all vrfs, it will have to be averaged out over all vrfs.
The number of VRFs dependant on directly provisioned VRFs (Y) will have to manually calculated because
it depends on the router configuration. For example, if route import targets in Dependant VRF import from
routes exported by other VRFs. A VRF is dependant if it depends on a nexthops being in some other VRF
which is directly provisioned. There is no show command to automatically calculate Y, since it depends
completely on the way router is configured to import routes in various VRFs.
BGP Accept Own
The BGP Accept Own feature enables handling of self-originated VPN routes, which a BGP speaker receives
from a route-reflector (RR). A "self-originated" route is one which was originally advertized by the speaker
itself. As per BGP protocol [RFC4271], a BGP speaker rejects advertisements that were originated by the
speaker itself. However, the BGP Accept Own mechanism enables a router to accept the prefixes it has
advertised, when reflected from a route-reflector that modifies certain attributes of the prefix. A special
community called ACCEPT-OWN is attached to the prefix by the route-reflector, which is a signal to the
receiving router to bypass the ORIGINATOR_ID and NEXTHOP/MP_REACH_NLRI check. Generally, the
BGP speaker detects prefixes that are self-originated through the self-origination check (ORIGINATOR_ID,
NEXTHOP/MP_REACH_NLRI) and drops the received updates. However, with the Accept Own community
present in the update, the BGP speaker handles the route.
One of the applications of BGP Accept Own is auto-configuration of extranets within MPLS VPN networks.
In an extranet configuration, routes present in one VRF is imported into another VRF on the same PE. Normally,
the extranet mechanism requires that either the import-rt or the import policy of the extranet VRFs be modified
to control import of the prefixes from another VRF. However, with Accept Own feature, the route-reflector
can assert that control without the need for any configuration change on the PE. This way, the Accept Own
feature provides a centralized mechanism for administering control of route imports between different VRFs.
BGP Accept Own is supported only for VPNv4 and VPNv6 address families in neighbor configuration mode.
Route-Reflector Handling Accept Own Community and RTs
The ACCEPT_OWN community is originated by the InterAS route-reflector (InterAS-RR) using an outbound
route-policy. To minimize the propagation of prefixes with the ACCEPT_OWN community attribute, the
attribute will be attached on the InterAS-RR using an outbound route-policy towards the originating PE. The
InterAs-RR adds the ACCEPT-OWN community and modifies the set of RTs before sending the new Accept
Own route to the attached PEs, including the originator, through intervening RRs. The route is modified via
route-policy.
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.1.x
OL-30423-03 61
Implementing BGP
BGP Accept Own
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