Ospf

control

Hi All,

Came across this when reading up on OSPF (which is still very new to me)

"When designing an OSPF backbone area, you should make sure there is little or no possibility of the backbone area being split into two or more parts by a router or link failure. If the OSPF backbone is split due to hardware failures or access lists, sizeable areas of the network will become unreachable"

Does anyone have a diagram that visualises the statement? I'm having a hard time trying to understand what the above means.

martell1000

i guess they mean something like that

where the failure of one link would leave 2 seperate groups of routers

control

Ah I see. So we would be talking about the middle link in this case?

martell1000

yes - if this one goes down you area is beeing split in half.

njkt

What would be the optimal design in this case then?

Greenmet29

I'd imagine a design that is completely redundant.

martell1000

which would be called a "full mesh" but you will never see this if you have more than 3 or 4 routers in an area. it always depends on your budget and on the topology. just keep in mind that you dont have a design where a singe link outage leads to a seperation. in other words: do not chain routers - use star or ring topologys if possible.