Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 381)

A VLAN ACL requires an IVID allocation for the target VLAN. If the target VLAN is configured on the
local switch port, the ACL can be applied on the IVID for this VLAN. However, on the switch where the
VLAN is transiting (that is, it is not configured on any switch port), an IVID must still be allocated for the
ACL entry. The maximum number of VLANs that can be configured on the switch is determined by the
maximum number of IVIDs minus the number of transit VLAN ACLs that are configured on the switch.
Brocade VDX 6740 series limitations
The Brocade VDX 6740 series RBridge supports a total of 6096 (4096 + 2000) VLANs, 4096 of which
must be 802.1Q VLANs. The other 2000 VLANs can be configured as service VFs, assuming that the
VLAN is configured on a single port. This limitation comes from the VPN table size on this platform.
VLAN virtualization
When a cloud computing provider provisions a virtual datacenter by replicating server-rack ports on
demand (PODs) across server ports, different tenant domains exist but with overlapping 802.1Q VLANs
at the server ports. The tenant domains are isolated by mapping the 802.1Q VLAN at each interface
into a different VLAN forwarding domain. This capability allows the switch to support more than the 4K
VLANs permitted by the 802.1Q address space.
In the example VMware topology shown below, the data center has three PODs, provided by RBridges
RB1, RB2, and RB3. All three PODs (VMware ESXi hypervisors 1 through 3) have an identical pre-
installed configuration. Each POD supports two tenants. The first tenant can have two applications
running on VFs 10 and 20. The other tenant has only one application, running on VF 30. Here, four
tenant applications are provisioned. Tenant 1 and 2 applications run on ESX1 and ESX2. Tenant 3 and
4 applications run on ESX3.
VLAN virtualization
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