Thank you for your difficult work. I have a question - does the scheme provide for the possibility of direct communication between regions? As a protection route, for example. Thank you.
Sure, you could have a router that runs both regions processes. It would then run BGP-LU and forward the BGP-LU advertisement from 1 PE to the other. Quite hard to explain just in writing :) Anyway, this wouldn't scale also. Big SP's have like tens of regions, directly connecting each region to each other is almost impossible.
Hello. In the Alcatel-Lucent Versatile Routing and Services with BGP book by Bookham, mentions that there shouldn't be direct communication between aggregation regions, instead it should go through the core.
@@felixruiztorrez5192 yes, this is correct. This is how it should be done in real world networks, but in the lab you can do anything you wish. And what I was saying before was that we could have direct communication between regions. It would work from a protocol perspective, but it beats the whole purpose of segmentation per regions.
Your example is wrong. Seamless MPLS can be used only with OSPF, not with ISIS. I can explain. The ISIS connection between R3(P) and R4(ABS) is Level 2 connection, because only Level 2 connection could be used with 2 different areas. That means that R3 is L1/L2 router, so he KNOW the path to 9.9.9.9 without BGP. And you will run LDP only within each IGP domain there woulnd be a LSP from R1 to R4 (i mean, if you use ISIS).
Hey! The trick is that you run different ISIS processes in each IGP domain, not different areas/levels. You don't redistribute between the processes so you don't leak prefixes between the IGP domains.
Excellent explanation
Gracias !!!!!
Thank you so much, it is one of the best and the most clear explanation of Seamless MPLS
Glad you think so!
so what about if the core has a RR, so all ABRs in the core network establish a BGP-LU session with the RR ?
Thanks , very good job and very clear explanation ❤
You are welcome!
Beatifull explanation !
I wonder , how SR MPLS can resolve the same situation , have you any other video when you explain this , whit SR mpls ? Thanks in advance.
Thankyou well explained, please also make a video on BGP-LU as u mentioned.
Thanks! BGP-LU is in plan, yes.
Will label be regenerated for IBGP on ABR ?
Thank you for your difficult work. I have a question - does the scheme provide for the possibility of direct communication between regions? As a protection route, for example. Thank you.
Sure, you could have a router that runs both regions processes. It would then run BGP-LU and forward the BGP-LU advertisement from 1 PE to the other. Quite hard to explain just in writing :) Anyway, this wouldn't scale also. Big SP's have like tens of regions, directly connecting each region to each other is almost impossible.
Hello. In the Alcatel-Lucent Versatile Routing and Services with BGP book by Bookham, mentions that there shouldn't be direct communication between aggregation regions, instead it should go through the core.
@@felixruiztorrez5192 yes, this is correct. This is how it should be done in real world networks, but in the lab you can do anything you wish. And what I was saying before was that we could have direct communication between regions. It would work from a protocol perspective, but it beats the whole purpose of segmentation per regions.
Your example is wrong. Seamless MPLS can be used only with OSPF, not with ISIS. I can explain. The ISIS connection between R3(P) and R4(ABS) is Level 2 connection, because only Level 2 connection could be used with 2 different areas. That means that R3 is L1/L2 router, so he KNOW the path to 9.9.9.9 without BGP. And you will run LDP only within each IGP domain there woulnd be a LSP from R1 to R4 (i mean, if you use ISIS).
Hey! The trick is that you run different ISIS processes in each IGP domain, not different areas/levels. You don't redistribute between the processes so you don't leak prefixes between the IGP domains.