H3C Technologies H3C S7500E Series Switches - Manual (Page 153)

5-8
Figure 5-6 PDU common header format
Intradomain routing protocol discriminator
Reserved
Version
R
ID length
Version/Protocol ID extension
Length indicator
Maximum area address
R R PDU type
No. of Octets
1
1
1
1
1
1
1
1
z Intradomain Routing Protocol Discriminator: Set to 0x83.
z Length Indicator: Length of the PDU header in bytes, including both common and specific
headers.
z Version/Protocol ID Extension: Set to 1(0x01).
z ID Length: Length of the NSAP address and NET ID.
z R(Reserved): Set to 0.
z PDU Type: For details, see Table 5-1 .
z Version: Set to 1(0x01).
z Maximum Area Address: Maximum number of area addresses supported.
Table 5-1 PDU type
Type PDU Type Acronym
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
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