external attribute lsa and opaque...

so, here we have the avoided/able lsa types, brought to you by
http://www.inetdaemon.com/tutorials/internet/ip/routing/ospf/index.shtml 

Types (by type code)

• 1 - Router LSA
• 2 - Network LSA
• 3 - Network summary LSA
• 4 - ASBR Summary LSA
• 5 - AS External LSA
• 6 - Group Membership LSA
• 7 - NSSA External LSA
• 8 - External Attributes LSA
• 9 - Opaque LSA (link-local scope)
• 10 - Opaque LSA (area-local scope)
• 11 - Opaque LSA (AS scope)

6 mentions group membership, that's a give away... can you say mospf... cisco seems to avoid it but john moy does not in rfc1585...

MOSPF routers use the IGMP protocol to monitor multicast group
   membership on local LANs through the sending of IGMP Host Membership
   Queries and the reception of IGMP Host Membership Reports.

to the moon, alice...

number 8 is a give away as well... attributes? hmmm...

from wiki:

• Type 8 - A link-local only LSA for OSPFv3. A Type 8 LSA is used to give information about link-local addresses and a list of IPv6 addresses on the link. In OSPFv2, however, the Type 8 was originally intended to be used as a so-called External-Attributes-LSA for transit autonomous systems where OSPFv2 could replace the internal Border Gateway Protocol (iBGP). In these networks, the BGP destinations would be carried in LSA Type 5 while their BGP attributes would be inserted into LSA Type 8. Most OSPFv2 implementations never supported this feature.

• Type 9 - a link-local "opaque" LSA (defined by RFC2370) in OSPFv2 and the Intra-Area-Prefix LSA in OSPFv3. It is the OSPFv3 LSA that contains prefixes for stub and transit networks in the link-state ID.

• Type 10 - an area-local "opaque" LSA as defined by RFC2370. Opaque LSAs contain information which should be flooded by other routers even if the router is not able to understand the extended information itself. Typically type 10 LSAs are used for traffic engineering extensions to OSPF, flooding extra information about links beyond just their metric, such as link bandwidth and color.

• Type 11 - an AS "opaque" LSA defined by RFC 5250, which is flooded everywhere except stub areas. This is the opaque equivalent of the type 5 external LSA.^[3]

 opaque means you can't see through it (won't let light through) or obscure...

that concludes your ospf trivia for tonight...