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This policy configures the network control settings for the Cisco UCS domain, including the following:
Whether the Cisco Discovery Protocol (CDP) is enabled or disabled
How the virtual interface ( VIF) behaves if no uplink port is available in end-host mode
The action that Cisco UCS Central takes on the remote Ethernet interface, vEthernet interface , or vFibre Channel interface when the associated border port fails
Whether the server can use different MAC addresses when sending packets to the fabric interconnect
Whether MAC registration occurs on a per-VNIC basis or for all VLANs
By default, the Action on Uplink Fail property in the network control policy is configured with a value of link-down. For adapters such as the Cisco UCS M81KR Virtual Interface Card, this default behavior directs Cisco UCS Central to bring the vEthernet or vFibre Channel interface down if the associated border port fails. For Cisco UCS systems using a non-VM-FEX capable converged network adapter that supports both Ethernet and FCoE traffic, such as Cisco UCS CNA M72KR-Q and the Cisco UCS CNA M72KR-E, this default behavior directs Cisco UCS Central to bring the remote Ethernet interface down if the associated border port fails. In this scenario, any vFibre Channel interfaces that are bound to the remote Ethernet interface are brought down as well.
Note | if your implementation includes those types of non-VM-FEX capable converged network adapters mentioned in this section and the adapter is expected to handle both Ethernet and FCoE traffic, we recommend that you configure the Action on Uplink Fail property with a value of warning. Note that this configuration might result in an Ethernet teaming driver not being able to detect a link failure when the border port goes down. |
MAC addresses are installed only on the native VLAN by default, which maximizes the VLAN port count in most implementations.
Note | If a trunking driver is being run on the host and the interface is in promiscuous mode, we recommend that you set the Mac Registration Mode to All VLANs. |
Ethernet adapter policies govern the host-side behavior of the adapter, including how the adapter handles traffic. For example, you can use these policies to change default settings for the following:
Queues
Interrupt handling
Performance enhancement
RSS hash
Failover in an cluster configuration with two fabric interconnects
By default, Cisco UCS provides a set of Ethernet adapter policies. These policies include the recommended settings for each supported server operating system. Operating systems are sensitive to the settings in these policies. Storage vendors typically require non-default adapter settings. You can find the details of these required settings on the support list provided by those vendors.
Note | We recommend that you use the values in these policies for the applicable operating system. Do not modify any of the values in the default policies unless directed to do so by Cisco Technical Support. |
If you are creating an Ethernet adapter policy (instead of using the default Windows adapter policy) for a Windows operating system, you must use the following formulas to calculate values that work with Windows:
Completion Queues = Transmit Queues + Receive QueuesInterrupt Count = (Completion Queues + 2) rounded up to nearest power of 2
For example, if Transmit Queues = 1 and Receive Queues = 8 then:
Completion Queues = 1 + 8 = 9
Interrupt Count = (9 + 2) rounded up to the nearest power of 2 = 16
The dynamic vNIC connection policy determines how the connectivity between VMs and dynamic vNICs is configured. This policy is required for Cisco UCS domains that include servers with VIC adapters on which you have installed VMs and configured dynamic vNICs.
Each dynamic vNIC connection policy includes an Ethernet adapter policy and designates the number of vNICs that can be configured for any server associated with a service profile that includes the policy.
The Cisco user-space NIC (Cisco usNIC) connection policy page displays the details of your usNIC connection policy and what service profiles it is associated with.
VMQ provides improved network performance to the entire management operating system. From Cisco UCS Central you can create a VMQ connection policy for a vNIC on a service profile. To configure the VMQ vNIC on a service profile for a server, at least one adapter in the server must support VMQ. Make sure the servers have at least one the following adapters installed:
You must have one of the following Operating systems to use VMQ:
When you select the vNIC connection policy for a service profile, make sure to select one of the three options such as Dynamic, usNIC or VMQ connection policy for the vNIC. You can apply only any one of the vNIC connection policies on a service profile at any one time.
When you have selected VMQ policy on the vNIC for a service profile, you must also have the following settings in the service profile:
Configuring a VMQ vNIC connection policy involves the following:
Associate the VMQ connection policy with a vNIC, vNIC template, or LAN connectivity policy.
LAN connectivity policies determine the connections and the network communication resources between the server and the LAN on the network. These policies use pools to assign MAC addresses to servers and to identify the vNICs that the servers use to communicate with the network.
Note | These policies are included in service profiles and service profile templates, and can be used to configure multiple servers. So, using static IDs in connectivity policies is not recommended. |
Connectivity policies enable users without network or storage privileges to create and modify service profiles and service profile templates with network and storage connections. However, users must have the appropriate network and storage privileges to create connectivity policies.
Connectivity policies require the same privileges as other network and storage configurations. For example, you must have at least one of the following privileges to create connectivity policies:
After the connectivity policies have been created, a user with ls-compute privileges can include them in a service profile or service profile template. However, a user with only ls-compute privileges cannot create connectivity policies.
Step 1 | In the
Actions bar, type
Create LAN Connectivity Policy and press
Enter.
| ||
Step 2 | In the LAN Connectivity Policy dialog box, click Basic and choose the Organization in which you want to create the policy. | ||
Step 3 | Enter the
Name and optional
Description.
The name is case sensitive. | ||
Step 4 | In vNICs, create one or more vNICs and select the properties. You can manually create the vNIC, use a vNIC template, or create a redundancy template pair. For more information, see vNIC Templates. | ||
Step 5 | In
iSCSI
vNICs, enter the
iSCSI
vNIC and enter the appropriate properties values.
| ||
Step 6 | Click Create. |
UniDirectional Link Detection (UDLD) is a Layer 2 protocol that enables devices connected through fiber-optic or twisted-pair Ethernet cables to monitor the physical configuration of the cables and detect when a unidirectional link exists. All connected devices must support UDLD for the protocol to successfully identify and disable unidirectional links. When UDLD detects a unidirectional link, it marks the link as unidirectional. Unidirectional links can cause a variety of problems, including spanning-tree topology loops.
UDLD works with the Layer 1 mechanisms to determine the physical status of a link. At Layer 1, autonegotiation takes care of physical signaling and fault detection. UDLD performs tasks that autonegotiation cannot perform, such as detecting the identities of neighbors and shutting down misconnected interfaces. When you enable both autonegotiation and UDLD, the Layer 1 and Layer 2 detections work together to prevent physical and logical unidirectional connections and the malfunctioning of other protocols.
A unidirectional link occurs whenever traffic sent by a local device is received by its neighbor but traffic from the neighbor is not received by the local device.
UDLD supports two modes of operation: normal (the default) and aggressive. In normal mode, UDLD can detect unidirectional links due to misconnected interfaces on fiber-optic connections. In aggressive mode, UDLD can also detect unidirectional links due to one-way traffic on fiber-optic and twisted-pair links and to misconnected interfaces on fiber-optic links.
In normal mode, UDLD detects a unidirectional link when fiber strands in a fiber-optic interface are misconnected and the Layer 1 mechanisms do not detect this misconnection. If the interfaces are connected correctly but the traffic is one way, UDLD does not detect the unidirectional link because the Layer 1 mechanism, which is supposed to detect this condition, does not do so. In case, the logical link is considered undetermined, and UDLD does not disable the interface. When UDLD is in normal mode, if one of the fiber strands in a pair is disconnected and autonegotiation is active, the link does not stay up because the Layer 1 mechanisms did not detect a physical problem with the link. In this case, UDLD does not take any action, and the logical link is considered undetermined.
UDLD aggressive mode is disabled by default. Configure UDLD aggressive mode only on point-to-point links between network devices that support UDLD aggressive mode. With UDLD aggressive mode enabled, when a port on a bidirectional link that has a UDLD neighbor relationship established stops receiving UDLD packets, UDLD tries to reestablish the connection with the neighbor and administratively shuts down the affected port. UDLD in aggressive mode can also detect a unidirectional link on a point-to-point link on which no failure between the two devices is allowed. It can also detect a unidirectional link when one of the following problems exists:
UDLD operates by using two mechanisms:
Neighbor database maintenance
UDLD learns about other UDLD-capable neighbors by periodically sending a hello packet (also called an advertisement or probe) on every active interface to keep each device informed about its neighbors. When the switch receives a hello message, it caches the information until the age time (hold time or time-to-live) expires. If the switch receives a new hello message before an older cache entry ages, the switch replaces the older entry with the new one.
UDLD clears all existing cache entries for the interfaces affected by the configuration change whenever an interface is disabled and UDLD is running, whenever UDLD is disabled on an interface, or whenever the switch is reset. UDLD sends at least one message to inform the neighbors to flush the part of their caches affected by the status change. The message is intended to keep the caches synchronized.
Event-driven detection and echoing
UDLD relies on echoing as its detection mechanism. Whenever a UDLD device learns about a new neighbor or receives a resynchronization request from an out-of-sync neighbor, it restarts the detection window on its side of the connection and sends echo messages in reply. Because this behavior is the same on all UDLD neighbors, the sender of the echoes expects to receive an echo in reply.
If the detection window ends and no valid reply message is received, the link might shut down, depending on the UDLD mode. When UDLD is in normal mode, the link might be considered undetermined and might not be shut down. When UDLD is in aggressive mode, the link is considered unidirectional, and the interface is shut down.
If UDLD in normal mode is in the advertisement or in the detection phase and all the neighbor cache entries are aged out, UDLD restarts the link-up sequence to resynchronize with any potentially out-of-sync neighbors.
If you enable aggressive mode when all the neighbors of a port have aged out either in the advertisement or in the detection phase, UDLD restarts the link-up sequence to resynchronize with any potentially out-of-sync neighbor. UDLD shuts down the port if, after the fast train of messages, the link state is still undetermined.
The following guidelines and recommendations apply when you configure UDLD:
A UDLD-capable interface also cannot detect a unidirectional link if it is connected to a UDLD-incapable port of another switch.
When configuring the mode (normal or aggressive), make sure that the same mode is configured on both sides of the link.
UDLD should be enabled only on interfaces that are connected to UDLD capable devices. The following interface types are supported:
Link Aggregation combines multiple network connections in parallel to increase throughput and to provide redundancy. Cisco UCS uses Link Aggregation Control Protocol (LACP) to group uplink ethernet ports into a port channel. You can create an LACP policy in Cisco UCS Central to manage how a particular port channel uses LACP. The following port channel types support LACP:
A default LACP policy is automatically assigned to all port channels that you create. You can edit this LACP policy or create a new one and assign it to a port channel. The LACP policy controls the following:
Flow control policies determine whether the uplink Ethernet ports in a Cisco UCS domain send and receive IEEE 802.3x pause frames when the receive buffer for a port fills. These pause frames request that the transmitting port stop sending data for a few milliseconds until the buffer clears.
For flow control to work between a LAN port and an uplink Ethernet port, you must enable the corresponding receive and send flow control parameters for both ports. For Cisco UCS, the flow control policies configure these parameters.
When you enable the send function, the uplink Ethernet port sends a pause request to the network port if the incoming packet rate becomes too high. The pause remains in effect for a few milliseconds before traffic is reset to normal levels. If you enable the receive function, the uplink Ethernet port honors all pause requests from the network port. All traffic is halted on that uplink port until the network port cancels the pause request.
Because you assign the flow control policy to the port, changes to the policy have an immediate effect on how the port reacts to a pause frame or a full receive buffer.
Note | If you have selected global port configuration for Policy Resolution Control in Cisco UCS Manager, then all local flow control policies will be deleted, and global flow control policies belonging to the same domain group in Cisco UCS Central will be created in Cisco UCS Manager. |
A quality of service (QoS) policy assigns a system class to the outgoing traffic for a vNIC or vHBA. This system class determines the quality of service for that traffic. For certain adapters, you can also specify additional controls on the outgoing traffic, such as burst and rate.
You must include a QoS policy in a vNIC policy or vHBA policy and then include that policy in a service profile to configure the vNIC or vHBA.
Use the ID range access control policy to limit what pools can be utilized in a specific domain group. When you apply the access control policy to a pool, only the domain groups selected can access those pools.