RPKI implementation

["Jakob Heitz (jheitz)" <jheitz () cisco com>]

During the RPKI presentation there was a question about
resilience of the router if the RPKI cache loses connectivity.
The IOS-XR implementation allows multiple caches to be configured.
When a cache loses connectivity, the entries from that cache
are purged after a time interval. Default is 60 seconds and it is configurable.
A lookup of a prefix that is not loaded will return not-found.
5 seconds after the latest RPKI database update,
a refresh request is sent to each neighbor, provided that the neighbor either:
- dropped any received route due to a policy that contains validation-state, or
- received a route, the validation state of which changed.
If soft reconfiguration inbound is configured, then the refresh is avoided,
because the received paths are stored.

Thanks,
Jakob.