3com S7906E 설치 설명서

 

1-8 

Table 1-1 PDU type 

15 

Level-1 LAN IS-IS hello PDU 

L1 LAN IIH 

16 

Level-2 LAN IS-IS hello PDU 

L2 LAN IIH 

17 

Point-to-Point IS-IS hello PDU 

P2P IIH 

18 

Level-1 Link State PDU 

L1 LSP 

20 

Level-2 Link State PDU 

L2 LSP 

24 

Level-1 Complete Sequence Numbers PDU 

L1 CSNP 

25 

Level-2 Complete Sequence Numbers PDU 

L2 CSNP 

26 

Level-1 Partial Sequence Numbers PDU 

L1 PSNP 

27 

Level-2 Partial Sequence Numbers PDU 

L2 PSNP 

 

Hello packets are used by routers to establish and maintain neighbor relationships. A hello packet is 

also called an IS-to-IS hello PDU (IIH). For broadcast networks, the Level-1 routers use the Level-1 

LAN IIHs; and the Level-2 routers use the Level-2 LAN IIHs. The P2P IIHs are used on point-to-point 

networks. 

 illustrates the hello packet format in broadcast networks, where the blue fields are the 

common header. 

Figure 1-7 L1/L2 LAN IIH format 

 

 

z 

Reserved/Circuit Type: The first 6 bits are reserved with a value of 0. The last 2 bits indicate the 

router type. 00 means reserved, 01 indicates L1, 10 indicates L2, and 11 indicates L1/2.  

z 

Source ID: System ID of the router advertising the hello packet.