3com DUA1750-2BAA01 Manual De Usuario

3Com Switch 8800 Configuration Guide 

Chapter 20  Integrated IS-IS Configuration

 

20-6 

Sequence Number Packet (SNP) can confirm the LSPs last received from neighbors. 

SNPs function as acknowledge packets, but SNPs function more validly. SNP includes 

complete SNP (CSNP) and partial SNP (PSNP). SNP can be further divided into 

Level-1 CSNP, Level-2 CSNP, Level-1 PSNP and Level-2 PSNP. 

PSNP only lists one or more last received LSP sequence numbers, and confirms 

multiple LSPs. When detecting asynchronous LSDBs, the system asks neighbors to 

send new LSPs by PSNPs. 

CSNP contains all LSP digest information in a LSDB, synchronizing LSDBs for 

neighbor routers. On a broadcast network, a DIS sends CSNPs periodically (the default 

sending period is 10 seconds). On the point-to-point line, a DIS sends CSNPs only 

when the neighbors are established for the first time. 

Among the following configurations, the configuration of enabling integrated IS-IS is 

required, while other configurations are optional.  

IS-IS configuration includes:  

1) IS-IS 

basic 

configuration 

z 

z 

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