def update_rtc_as_set(self):
        """Syncs RT NLRIs for new and removed RTC_ASes.

        This method should be called when a neighbor is added or removed.
        """
        # Compute the diffs in RTC_ASes
        curr_rtc_as_set = self._neighbors_conf.rtc_as_set
        # Always add local AS to RTC AS set
        curr_rtc_as_set.add(self._core_service.asn)
        removed_rtc_as_set = self._all_rtc_as_set - curr_rtc_as_set
        new_rtc_as_set = curr_rtc_as_set - self._all_rtc_as_set

        # Update to new RTC_AS set
        self._all_rtc_as_set = curr_rtc_as_set

        # Sync RT NLRI by adding/withdrawing as appropriate
        for new_rtc_as in new_rtc_as_set:
            for import_rt in self._all_vrfs_import_rts_set:
                self._add_rt_nlri_for_as(new_rtc_as, import_rt)
        for removed_rtc_as in removed_rtc_as_set:
            for import_rt in self._all_vrfs_import_rts_set:
                self._add_rt_nlri_for_as(removed_rtc_as, import_rt,
                                         is_withdraw=True)