Cisco ACI L3 Out SVI IP Address

[zachartl]

Hello,

I've got a connection requirement where they're looking to connect a Host Blade to the Border Leaf switches using Trunk Ports. I've set up the Leaf Switches to support this, replete with Separate Interface Policies. I'm seeing in the L3 Out Guide that I can use the Same SVI IP Address within both Paths. 

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/guide-c07-743150.html

I've tried this but to no avail. I get an Error message stating this won't work. I wish it would and the only reason I'm asking you Folks is due to this page in the L3 Out Configuration Guide. Please see enclosed file.  Figure 17.

Thank you,

Terry

[zachartl]

Hello,

I just looked again at Figure 17. within the L3-Out Guide and it depicts using the Same SVI IP Address within the SAME NODE. We're using two different Nodes 201 and 202. Same L3-Out. The Controller Software is not letting us use the Same IP Address across Different Node/Paths and that might just be the way it is. 

Thank you again!

[Sergiu.Daniluk]

"We're using two different Nodes 201 and 202"

This is why it gives you the error. You cannot use the same IP address as primary IP on different nodes in a L3Out.

What you are looking for is secondary IP address:

Stay safe,

Sergiu

[zachartl]

Hey Sergiu,

I was looking at this yesterday too. But as I understand it, the Secondary IP Address can not be a route peer? Only the Primary IP Address?

And so I was considering using the Same Nodes so I could use the Same IP Addresses to connect the device. I'm not crazy about this idea but again, I'm not crazy about the entire connection requirement I've been given. 

Thank you Sir!

Terry

[Sergiu.Daniluk · Accepted solution]

This secondary IP address is useful to define a additional IP addresses when you require a common IP on two BL switches so that external devices can point to a single IP with a static route. Make sure you configure also a vPC towards the external router to ensure high availability. If you use a dynamic routing protocol, then then the secondary IP address is not really needed since the routing protocol itself will ensure ECMP and/or routing failover.

Stay safe,

Sergiu

[zachartl]

Hey Sergiu,

Sounds good, Thank you for you outstanding Help today, and your Time.

As always, Best Regards!

Terry

[zachartl]

Withdrawing this issue. I think this one will take care of itself for now. 

Thank you Everyone.