Exam H12-221 topic 1 question 127 discussion

RFC 1997 Well-known Communities The following communities have global significance and their operations shall be implemented in any community-attribute-aware BGP speaker. NO_EXPORT (0xFFFFFF01) All routes received carrying a communities attribute containing this value MUST NOT be advertised outside a BGP confederation boundary (a stand-alone autonomous system that is not part of a confederation should be considered a confederation itself). NO_ADVERTISE (0xFFFFFF02) All routes received carrying a communities attribute containing this value MUST NOT be advertised to other BGP peers. NO_EXPORT_SUBCONFED (0xFFFFFF03) All routes received carrying a communities attribute containing this value MUST NOT be advertised to external BGP peers (this includes peers in other members autonomous systems inside a BGP confederation).