Unified Fabric Port (UFP) is another approach to NIC virtualization. It is similar to vNIC but with enhanced flexibility and should be considered the direction for future development in the virtual NIC area for IBM switching solutions. UFP is supported today on the EN4093R 10Gb Scalable Switch and CN4093 10Gb Converged Scalable Switch.
UFP and vNIC are mutually exclusive in that you cannot enable UFP and vNIC at the same time on the same switch.
If a comparison were to be made between UFP and vNIC, UFP is most closely related to vNIC Virtual Fabric mode in that in both sides, the switch and the NIC/CNA share in controlling bandwidth usage, but there are significant differences. Compared to vNIC, UFP supports the following modes of operation per virtual NIC (vPort):
Access: The vPort only allows the default VLAN, which is similar to a physical port in access mode.
Trunk: The vPort permits host side tagging and supports up to 32 customer-defined VLANs on each vPort (4000 total across all vPorts).
Tunnel: Q-in-Q mode, where the vPort is customer VLAN-independent (this is the closest to vNIC Virtual Fabric dedicated uplink mode). Tunnel mode is the default mode for a vPort.
FCoE: Dedicates the specific vPort for FCoE traffic.
The following rules and attributes are associated with UFP vPorts:
They are supported only on 10 Gb internal interfaces.
UFP allows a NIC to be divided into up to four virtual NICs called vPorts per physical NIC (can be less than 4, but not more).
Each vPort can be set for a different mode or same mode (with the exception of the FCoE mode, which is limited only a single vPort on a UFP port, and specifically only vPort 2).
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By default, each vPort is ensured 2.5 Gb and can burst up to the full 10G if other vPorts do not need the bandwidth. The ensured minimum bandwidth and maximum bandwidth for each vPort are configurable.
The minimum bandwidth settings of all configured vPorts on a physical NIC cannot exceed 10 Gb.
Each vPort must have a default VLAN assigned. This default VLAN is used for different purposes in different modes.
This default VLAN must be unique across the other three vPorts for this physical port, which means that vPort 1.1 must have a different default VLAN assigned than vPort 1.2, 1.3 or 1.4.
When in trunk or access mode, this default VLAN is untagged by default, but it can be configured for tagging if wanted. This configuration is similar to tagging the native or PVID VLAN on a physical port. In tunnel mode, the default VLAN is the outer tag for the Q-in-Q tunnel through the switch and is not seen by the end hosts and upstream network.
vPort 2 is the only vPort that supports the FCoE setting. vPort 2 can also be used for other modes (for example, access, trunk or tunnel). However, if you want the physical port to support FCoE, this function can only be defined on vPort 2
Table 3-4 offers some check points in helping to select a UFP mode.
Table 3-4 Attributes of UFP modes
What are some of the criteria to decide if a UFP or vNIC solution should be implemented to provide the virtual NIC capability?
In an environment that has not standardized on any specific virtual NIC technology and does not need per logical NIC failover today, UFP is the way to go. As noted, all future virtual NIC development will be on UFP, and the per-logical NIC failover function will be available in a coming release. UFP has the advantage being able to emulate vNIC virtual fabric modes mode (via tunnel mode for dedicate uplink vNIC and access mode for shared uplink vNIC) but can also offer virtual NIC support with customer VLAN awareness (trunk mode) and shared virtual group uplinks for access and trunk mode vPorts.
If an environment has already standardized on Virtual Fabric mode vNIC and plans to stay with it, or requires the ability of failover per logical group today, Virtual Fabric mode vNIC is recommended.
Capability
IBM UFP vPort mode options
Access Trunk Tunnel FCoE
Support for a single untagged VLAN on the vPorta Yes Yes Yes No
Support for VLAN restrictions on vPortb Yes Yes No Yes
VLAN-independent pass-true for customer VLANs No No Yes No
Support for FCoE on vPort No No No Yes
Support to carry more than 32 VLANs on a vPort No No Yes No a. Typically a user sets the vPort for access mode if the OS uses this vPort as a simple untagged link. Both
trunk and tunnel mode can also support this, but are not necessary to carry only a single untagged VLAN. b. Access and FCoE mode restricts VLANs to only the default VLAN that is set on the vPort. Trunk mode
Note that switch independent mode vNIC is actually exclusive of the above decision making process. Switch independent mode has its own unique attributes, one being truly switch independent, which allows you to configure the switch without restrictions to the virtual NIC technology, other than allowing the proper VLANs. UFP and Virtual Fabric mode vNIC each have a number of unique switch-side requirements and configurations. The down side to Switch independent mode vNIC is the inability to make changes without reloading the server, and the lack of bidirectional bandwidth allocation.