3com S7906E Manuel De Montage

 

1-9 

z 

Holding Time: If no hello packets are received from the neighbor within the holding time, the 

neighbor is considered down.  

z 

PDU Length: Total length of the PDU in bytes. 

z 

Priority: DIS priority. 

z 

LAN ID: Includes the system ID and a one-byte pseudonode ID.  

 shows the hello packet format on the point-to-point networks. 

Figure 1-8 P2P IIH format 

 

 

Instead of the priority and LAN ID fields in the LAN IIH, the P2P IIH has a Local Circuit ID field. 

The Link State PDUs (LSP) carry 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, as shown in 

.