H3C Technologies H3C S10500 Series Switches - Manual (Page 157)

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Figure 58 L1/L2 LSP format
Major fields of the L1/L2 LSP are as follows:
• PDU length: Total length of the PDU in bytes
• Remaining lifetime: LSP remaining lifetime in seconds
• LSP ID: Consists of the system ID, the pseudonode ID (one byte) and the LSP fragment number (one
byte)
• Sequence number: LSP sequence number
• Checksum: LSP checksum
• P (Partition Repair): Only for L2 LSPs; it indicates whether the router supports partition repair.
• ATT (Attachment): Generated by a L1/L1 router for L1 LSPs only; it indicates that the router
generating the LSP is connected to multiple areas.
• OL (LSDB Overload): Indicates that the LSDB is not complete because the router has run out of
memory. Other routers will not send packets to the overloaded router, except packets destined to the
networks directly connected to the router. For example, in Figure 59 , Router A forwards packets to
Router C through Router B. Once other routers know the OL field of LSPs from Router B is set to 1,
Router A will send packets to Router C via Router D and Router E, but still send to Router B packets
destined to the network directly connected to Router B.