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hfakoor222
Participant

OSPF doesn't have complete view of other area, how this reduce traffic

Acording to 350 ENCOR exam book, pg167, when an OSPF area doesn't have a complete topology of another area this reduces traffic. How does this reduce traffic mI do not understand.

 

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MHM Cisco World
Advisor

Ospf traffic not data traffic,

Image all router inside one area you will have 

Alot of lsa1 and lsa2 in opsf db of each router this consume memory and cpu,

While divide it in to area,

Each area know only lsa1 and las2 of it area and lsa3 of other area not lsa1 and lsa2 of other area.

Add to that summay that can done in abr this reduce the opsf traffic in areas

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MHM Cisco World
Advisor

Ospf traffic not data traffic,

Image all router inside one area you will have 

Alot of lsa1 and lsa2 in opsf db of each router this consume memory and cpu,

While divide it in to area,

Each area know only lsa1 and las2 of it area and lsa3 of other area not lsa1 and lsa2 of other area.

Add to that summay that can done in abr this reduce the opsf traffic in areas

Just to expand a bit on the information already provided by @MHM Cisco World . . .

". . . opsf db of each router this consume memory and cpu,"

The mention of CPU is important, as OSPF computes routes, within an OSPF area, using Dijkstra’s shortest path algorithm, which, I recall, doesn't scale linearly as the area topology increases in size.  (The impact can be so critical, in later OSPF implementations, Cisco has provided OSPF iSPF.)

"Add to that summay that can done in abr this reduce the opsf traffic in areas"

Also, it's the ABR that can minimize what's sent into the OSPF area, by defining the type of OSPF area, like a stub area.