134
•
LAN ID
—Includes the system ID and a one-byte pseudonode ID.
shows the hello packet format on the point-to-point networks.
Figure 56
P2P IIH format
Instead of the priority and LAN ID fields in the LAN IIH, the P2P IIH has a Local Circuit ID field.
LSP packet format
The Link State PDU (LSP) carries link state information. LSP involves two types: Level-1 LSP and Level-2 LSP.
The Level-2 LSPs are sent by the Level-2 routers, and the Level-1 LSPs are sent by the Level-1 routers. The
Level-1-2 router can send both types of LSPs.
The two types of LSPs have the same format.