H3C S7500E Series Ethernet Switches Operation Manual

Operation Manual – IPv4 Routing
H3C S7500E Series Ethernet Switches Chapter 4 IS-IS Configuration
4-14
PSNP only contains the sequence numbers of one or multiple latest received LSPs. It
can acknowledge multiple LSPs at one time. When LSDBs are not synchronized, a
PSNP is used to request new LSPs from neighbors.
Figure 4-12 shows the PSNP packet format.
Figure 4-12 L1/L2 PSNP format
VI. CLV
The variable fields of PDU are composed of multiple Code-Length-Value (CLV) triplets.
Figure 4-13 shows the CLV format.
Figure 4-13 CLV format
Table 4-2 shows different PDUs contain different CLVs.
Table 4-2 CLV name and the corresponding PDU type
CLV Code Name PDU Type
1 Area Addresses IIH, LSP
2 IS Neighbors (LSP) LSP
4 Partition Designated Level2 IS L2 LSP
6 IS Neighbors (MAC Address) LAN IIH
7 IS Neighbors (SNPA Address) LAN IIH
8 Padding IIH