DRAG DROP
Drag the ISIS packet types to correct type definition.
Answer: 
Explanation:
There are four general types of packets, and each type can be Level 1 or Level 2.
•Intermediate System-to-Intermediate System Hello (IIH)—Used by routers to detect neighbors
and form adjacencies. In addition to the IIH, which is an IS-IS protocol data unit (PDU), there is an
ISH and an ESH, which are End System-to-Intermediate System (ES-IS) PDUs.
•Link-state packet (LSP)—There are four types of LSPs: Level 1 pseudonode, Level 1
nonpseudonode, Level 2
pseudonode, and Level 2 nonpseudonode.
•Complete sequence number PDU (CSNP)—CSNPs contain a list of all LSPs from the current
database.
CSNPs are used to inform other routers of LSPs that may be outdated or missing from their own
database.
This ensures that all routers have the same information and are synchronized. The packets are
similar to an OSPF database description packet.
•Partial sequence number PDU (PSNP)—PSNPs are used to request an LSP (or LSPs) andacknowledge receipt of an LSP (or LSPs).
