ACI Overlapping VLAN Pool

[packet2020]

Hi All,

I'm currently working on an ACI deployment that has a single tenant with a single static VLAN pool. The static VLAN pool has been configured with a single, static encap range of 2-4094, We only use a about 100 VLANs within range 1-1000 for static EPGs.

We are looking to setup VMM integration using VLAN range 3XXX for dynamic assignment. From my understanding, I need to create a new Dynamic VLAN pool with range 3XXX, however I'm not sure if this will clash with my existing static pool. Will I have an issue here, and is it better if I change the existing static VLAN pool to use encap range 2-2999 so avoid any possible clashes with the dynamic pool?

Thanks

[M02@rt37]

Hello @packet2020,

It is best to avoid any overlapping VLAN ranges to ensure proper functioning and avoid any unintended issues.

To prevent conflicts, you can adjust the existing static VLAN pool to use an encapsulation range that does not overlap with the dynamic VLAN pool. For example, changing the static VLAN pool to use an encapsulation range of 2-2999 would provide separation from the dynamic VLAN pool in the 3XXX range.

By doing this, you ensure that the static and dynamic VLAN pools have distinct and non-overlapping VLAN ranges, allowing for proper assignment and management of VLANs in your ACI deployment.

[RedNectar]

Hi @packet2020 ,

The problem with overlapping VLAN pools occurs when a port is connected in its access policy chain to two VLAN pools where a particular VLAN exists in both pools.

Now if the pools are linked by different types of Domains (one via a physical domain and the other by a VMM domain) I don't believe there will be a problem - BUT I'm only 90% sure of that (if I get tome to do some research I'll update this answer, or if someone else can verify 

And if the VMM Domain is linked to a different AAEP than the Physical Domains that use the existing large VLAN pool, you won't have a problem

And be aware that changing a VLAN pool encapsulation range IS NOT A TRIVIAL TASK - every port that uses any of the VLANs in the range 2-4094 (in your case) WILL GO DOWN during the process.

Apart from that M02@rt37 's answer is spot on