how to compare performance after tune OSPF network

[Maivoko]

besides fast convergence time and least number of topology change

which command and in which content can compare performance after tune OSPF network

[Joseph W. Doherty]

Transfer performance, within your network shouldn't change when you "tune" OSPF.

As you note, what you should see (in some cases) is faster convergence.

I cannot recall any tools designed to measure that.

You could try something like stopping advertising a network on one end of the network and measuring how fast the other end of the network receives the change. Likewise flapping a route (i.e. its addition and withdrawal) and measure the difference in impact.

[Maivoko]

Will flapping event terminate the connection of tcp?

how flapping event influence tcp connection and udp connection?

[Joseph W. Doherty]

Flapping might break connections if the route is lost for an extended amount of time.

[Maivoko]

How to reduce number of flapping event to zero permanently and ensure never have flapping event?

[Joseph W. Doherty]

"ensure never", unsure anyone knows the answer to that.

Technologies like "dampening", though can mitigate the impact.

[Maivoko]

What cause flapping event?

can network device return to no flapping event occur itself?

what should do when flapping event occur?

[Joseph W. Doherty]

Often cause by a poor connection where routing hellos are lost. Might also be caused by congestion is routing hellos are dropped.

Don't understand your second question.

What to do? Identify cause and mitigate.

[Maivoko]

If in real practice hello lost only happen one time , how do you know the cause come from hello lost or congestion?

any command show?

i mean if real practice it happen flap

but in debug or testing it did not happen,

how to identify the cause?

[Joseph W. Doherty]

You often ignore a single event.

However, if there's a flap, you trace to the cause.

As to what commands to use and/or how to identify, you might start by readining Cisco's troubleshooting notes on their main site.

[rasmus.elmholt]

Hi

I would configure NTP, configure the logging timestamp msec service, and then debug ip routing when you do the tests.

Regards.