NLSR

Even though #4117 is not yet in the wild as a release version and it does not appear to be necessary, nevertheless Ashlesh has found an incidence in the testbed logs of routers receiving their own updates.

For the record, it is not known at this point why routers can receive their own sync updates, because:

• NFD should not send a Data back to the Face it just received it from, even if there is a breadcrumb trail leading there.
• NFD can detect if a Data is looping through use of the nonce, and should not use that Data, even if it comes from another Face.
• ChronoSync should be cancelling any pending Interests when it publishes an update, anyway.

However, it seems to be the case that routers can receive their own updates, so it is necessary to check that the updates are from ourself.