OSPF Loop Prevention

[@azeyn2050]

This vid is still only one in ospf loop prevention on youtube. Thanks again man!

[@ccnpseth4563]

Thabk you Thats why i started my channel

[@martysdomain]

This is a great demonstration of OSPF and virtual links.

[@bog5620]

i don't usually comment but you nailed in 2 minutes. i spent 3 days searching answers on YT and google, to questions like "why is mandatory to connect everything to area 0, why non backbone ABRs are not advertising networks or why ospf behave strange if you don't use the standard area 0 topology" everyone uses the standard to prevent loops. lol but none gives example of loops so people understand this protocol. thanks and good luck.

[@ccnpseth4563]

Yes sir, i asked the same exact thing. So thats why did this video. Thanks for the comment

[@leoxu3620]

from a CCIE view, it is a great video! I guess one thing is SPF will guarantee loop-free in area. then inter-area is done by leaf-spine-leaf topology.

[@ccnpseth4563]

Yes, the thing about OSPF is that it relies on area 0 as a transit area. Basically, if you are not Area 0 and a router is not routing you through area 0, then you cannot go through that area.

[@heribertorios]

In addition to virtual links you can use Gre tunnels to connect R3 to Backbone area. Try it just for fun. Thanks for the video. very good explanation.

[@justmeva]

It was a bit long, but it was loaded with a ton of information - thank you.

[@humayunakhtar2116]

For the first time ever i'm ale to get this topic . Thank you very much

[@grahammccann8554]

Hi CCNP Seth, Thank you for taking the time to make this video

[@ouoQAQ]

Really good content, helped me to review these topics

[@ahmedmagdy1118]

Thanks a lot for this informative video, I was confused before watching that video. Thanks again :)

[@DaughterOfRnbSoul]

Hey man thanks a lot ! I just recently passed the ICND1, and I knew how ripv2 avoids loops using split horizon and how EIGRP avoids loops but I never really understood how OSPF avoids loops :O

[@ccnpseth4563]

DaughterOfRnbSoul you are welcome, it was a mystery to me as well but then I found it so I decided to share it

[@kosmonautofficial296]

Interesting video thanks!

[@kashifrana6798]

Great explanation !

[@MrAbapper]

"Abrs will accept and use type 3 lsas learned from non backbone areas if it does not have a full adjacency with area 0"? What u mean? Third slide, u just said abrs will not use lsas from R3 because R3 doesnt have full adjency to area 0????

[@ashay710]

As we can see R1 learns about 5.5.5.5 from R3 but i guess its not using that info for path selection as it has a lover sequence number

[@MissFatalKisses]

Thanks for this! I've been looking for a good explanation of OSPF loop prevention =)

[@ccnpseth4563]

MissFatalKisses you're welcome.

[@tayoskeeper]

Nice video! You must be CCIE nowadays, for sure 👌🏻

[@sp3ktr3]

What If: area 1 is a loop that connects to two Different area 0 ABRs and then you have a dropped area 1 link that splits area 1 in two. How do you prevent dropped traffic between the two halves of area 1.

[@ccnpseth4563]

So you can have multiple areas w the same number, the concept is that routes from an area must transit area 0 to get to another area regardless of the number, even if area 1 is split

[@sp3ktr3]

In my experience it breaks the Routing. At least with route summarization. The fix for me is two gave two links between the ABRs, one as part of area 0, and the other as the other area.

[@DileepYadav-cn3zt]

You nailed it man

[@georgesmith3022]

So just adding a loopback to area 0 makes the router ABR?

[@adheipsingh1797]

thanks for the video man , great video

[@mohammedazarudeen7944]

How is loop is prevented in inside a area.i mean intra area loop prevention

[@MK1985-z7k]

This is an exact explanation by petr lapukov

[@ccnpseth4563]

Manoj Kumar it is, I needed to remember this, so I decided to do a video

[@ajeyganesh7843]

very helpful :)