OSPF and Higher sequence

I read when each router receives the LSU and the entry already exists but the LSA have a higher sequence number the router adds the entry to its LSDB.

My question is why router adds this LSA that already exists (it was duplicated), why just update it with a new version.

BR,
Auos.

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Comments

networker050184

Not sure what you are asking here. Are you asking why a router uses an LSA with a higher sequence number?

If that is your question, the router uses the higher sequence number because it is a newer version of the LSA and might contain new information. All routers in the are need to have the same version of the LSDB.

jrs91

auos wrote: »

I read when each router receives the LSU and the entry already exists but the LSA have a higher sequence number the router adds the entry to its LSDB.

My question is why router adds this LSA that already exists (it was duplicated), why just update it with a new version.

BR,
Auos.

Cisco probably designed it this way because it consumes less resources to just replace it entirely than it would to check whether every item within the LSA was modified.