LSA
1 router lsa router link advertisements within an area
2 network lsa dr link advertsiements within an area
3 summary lsa abr network advertisements between areas
4 summary abr network advertisements between areas
5 external lsa asbr edternal route advertsiements
6 multacast lsa multicast advertsiements
7 nssa external lsa nssa asbr external route advertsiemetns
8 external attribute lsa for bgp bgp advertsiements
9-11 opaque lsa for future use
