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is CDP/LLDP adjacency is required for vmm integration ?

Level 1
Level 1

Hi All,

I did a vmm testing today and played around it with available options, we can associate vmm domain with an epg either with immediate or pre-provision option for Resolution immediacy.

Tested with

A.CDP OFF and LLDP OFFàvSwitch policy of vmm+vmm domain with (immediate, preprovision) option

Under EPG learning, we observed the endpoint is learnt via blade vPC

Outcome, vlan is programmed in all interfaces in the leaf

B.CDP ON àvswitch policy of vmm + vmm domain with (immediate, pre-provision) option

Under EPG learning, we observed the endpoint is learnt via blade vPC and also vmm

Outcome, vlan is programmed only in the specfic interface (nothing but the uplink towards chassis)

Would like to know why CDP/LLDP adjacency is required for vmm integration though I am able to deploy using option A and still can see endpoints in EPG operational TAB and all works fine?

refer screenshot




3 Replies 3

Hi @ndhan302 
Yes, Pre-Provision removes all requirements for deploying the VLANs over the Leaf ports in VMM integration. As such, it is only advised for mission critical EPGs like iSCSI or vmk used for management through the fabric.

This feature was introduced to ACI on version 1.1(1j) to resolve a chick-and-egg situation.

Let's say the management vmk0 is on the ACI DVS and then the ESXi host reboots. The vlans will be removed from the interfaces until the ESXi host comes up and starts transmitting the CDP or LLDP control packets. When the ESXi host comes up however, it won't be able to talk to vCenter to get its configuration so the ESXi host won't be doing CDP or LLDP and thus the vlans will never get programmed.


Thanks HTH, so If i set "pre-provision" option, all vlans will be programmed on all the ports which is part of AEP. however in future if i move esx to another leaf, do same vlans will get programmed in new leaf? or do i need to redploy vmm in all EPG's?




Hi @ndhan302,

I'd expect APIC to program the VLANs in the new Leaf at the moment the interfaces connecting to the ESXi host come up since those interfaces would be associated with that same AEP.


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