A.Link B.NSSA external C.Network link D.Intra-area prefix E.AS domain
A.6to4 B.6over4 C.ISATAP D.6PE E.GRE
A.Prepend extra AS hops to the BGP prefix. B.Advertise more specific BGP prefixes(longer mask). C.Add(prepend)one or more communities to the prefix that is advertised by BGP. D.Have BGP dampen the prefix.