H3C Technologies H3C S12500 Series Switches - Manual (Page 156)

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Figure 60 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 (1 byte) and the LSP fragment number (1
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 runs out of memory.
In this case, 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 61 , 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 through Router D and Router E, but still send to Router B
packets destined to the network directly connected to Router B.
• IS type—Type of the router generating the LSP.