H3C Technologies H3C SR8800 User Manual
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Figure 58 LSDB overload
SNP
A sequence number PDU (SNP) acknowledges the latest received LSPs. It is similar to an Acknowledge
packet, but more efficient.
SNP involves Complete SNP (CSNP) and Partial SNP (PSNP), which are further divided into Level-1 CSNP,
Level-2 CSNP, Level-1 PSNP and Level-2 PSNP.
CSNP covers the summary of all LSPs in the LSDB to synchronize the LSDB between neighboring routers.
On broadcast networks, CSNP is sent by the DIS periodically (10s by default). On point-to-point networks,
CSNP is only sent during the adjacency establishment.
Figure 59 L1/L2 CSNP format
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.
- H3C SR6600-X H3C SR6600 H3C WX6000 Series Access Controllers H3C WX5000 Series Access Controllers H3C WX3000 Series Unified Switches H3C LSWM1WCM10 Access Controller Module H3C LSWM1WCM20 Access Controller Module H3C LSQM1WCMB0 Access Controller Module H3C LSRM1WCM2A1 Access Controller Module H3C LSBM1WCM2A0 Access Controller Module