Accepted Solutions
Hi @deepak21bhandari ,
Why can't we connect apic to leaf uplink ports and spine ports?
Let me approach this one with a question. Why would you want to connect a device that has 10G or 25G ports (i.e. an APIC) to uplink ports that are 40G or 100G? To me, that doesn't make a lot of sense. If you can give me a good reason WHY you'd actually want to do that, I'll put some time into explaining it a bit more.
My 2nd question is, can we connect leaf to leaf directly?
No. If you do, they will discover that they are connected (via LLDP) and shut the ports down. Connecting leaf-to-leaf breaks the whole Clos topology, so it makes sense to not allow this. However, there has been an exception case created since ACI V5.2(1) that allows two remote leaves to be connected to each other so traffic between the leaves in the remote location doesn't have to hairpin back to a Spine somewhere. (See https://www.cisco.com/c/en/us/td/docs/dcn/aci/apic/5x/release-notes/cisco-apic-release-notes-521.html and https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-740861.html - here's a pic from that paper)
Hi @deepak21bhandari ,
Why can't we connect apic to leaf uplink ports and spine ports?
Let me approach this one with a question. Why would you want to connect a device that has 10G or 25G ports (i.e. an APIC) to uplink ports that are 40G or 100G? To me, that doesn't make a lot of sense. If you can give me a good reason WHY you'd actually want to do that, I'll put some time into explaining it a bit more.
My 2nd question is, can we connect leaf to leaf directly?
No. If you do, they will discover that they are connected (via LLDP) and shut the ports down. Connecting leaf-to-leaf breaks the whole Clos topology, so it makes sense to not allow this. However, there has been an exception case created since ACI V5.2(1) that allows two remote leaves to be connected to each other so traffic between the leaves in the remote location doesn't have to hairpin back to a Spine somewhere. (See https://www.cisco.com/c/en/us/td/docs/dcn/aci/apic/5x/release-notes/cisco-apic-release-notes-521.html and https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-740861.html - here's a pic from that paper)
