is multiple vlans encap in the same EPG possible?

[JunSungKim2765]

hi, i'm a ACI newbie.

Is one vlan a one epg, correct?

If i have 50 vlans, should i create 50 EPGs?

I tried to include mutiple vlans into one EPG with static ports.

But the APIC displayed error msg when I included the second vlan into the same EPG.

If i create 50 EPGs, how can i contact among EPGs? Too many contracts are needed and it's hard to manage them.

thank you

best regards

[RedNectar · Accepted solution]

Hi @JunSungKim2765 ,

---

Is one vlan a one epg, correct?

No. But ACI is often configured that way.

If i have 50 vlans, should i create 50 EPGs?

No. But ACI is often configured that way.

I tried to include mutiple vlans into one EPG with static ports.

But the APIC displayed error msg when I included the second vlan into the same EPG.

Without knowing the error, I can't explain this. BUT there are some restrictions on multiple VLANs on the same EPG. 

• You can only statically map one VLAN per EPG per port
  • (You can fudge a 2nd VLAN on the same EPG on a port if you map the 2nd VLAN via the AAEP)
• A typical scenario where mor that one VLAN is used for an EPG is if a legacy VLAN is mapped to an EPG then a new dynamically mapped VLAN is allocated via a VMM (Virtual Machine Manager)

If i create 50 EPGs, how can i contact among EPGs? Too many contracts are needed and it's hard to manage them.

There are several tools to help

• Master Contracts
• The Preferred Group
• Multiple Application Profiles and Contracts with Applicatio Profile scope

[AshSe]

Hello @JunSungKim2765 

Before answering your queries, let me tell you that the VLANs in ACI have local significance. Having this being said, VLANs inside the ACI fabric take on different roles like FD VLAN, BD VLAN, HW VLAN, VNID, etc.

Secondly, creating VLANs (static/dynamic) is the very first step of physical/access policy configuration. I believe you are clear about the flow of configuration.

Creating EPG is the last step in the logical configuration.

• Tenant > VRF > BD > AP > EPG

Once EPGs are configured, you need to do either static or dynamic association.

Keeping all the above points in front, IMHO you will be able to draw the correct answer to your question.