OSPF Transit Area

[CSCO11508096]

Hi,

I am confused about creating Virtual link in transit area.

If transit capabilities are enabled at ospf router than do we need to creat virtual links for connecting the discontiguous remote area to are 0.

As i learnt transit capable routers discover the sortest path through the transit area. If it is so than what is the need of creating virtual link.

Thanks

Shashi Mishra

[Julio Carvajal]

Hello,

You got to remind that we still have the rule of thumb in OSPF about loop prevention that states that Area 0 must be the center of the universe, all of the other areas need to connect to Area 0 (You can use a virtual-link to prevent this)

Now, what's up with The OSPF area Transit?

Well basically this feature (enabled by default on 12.3T and later) enables an OSPF area to transport traffic from different areas (including backbone areas or not) but you still need a virtual-link if want to do it for non-backbone areas.

If you disable this capability you will be basically telling this router that a non-backbone area cannot be used to transport traffic between diff areas.

I hope I was clear

Read this and you will be good to go

http://blog.ine.com/2009/09/14/understanding-ospf-transit-capability/

For more information about Core and Security Networking follow my website at http://laguiadelnetworking.com

Any question contact me at jcarvaja@laguiadelnetworking.com

Cheers,

Julio Carvajal Segura

[CSCO11508096]

Thanks Julio,

Information shared by you is helpful.

Thanks

Shashi