Configuring Network Datalinks

Network datalinks manage devices, and are used by interfaces. A datalink can be a VLAN, VNIC, IB Partition, or an LACP aggregation of devices.

• Virtual LAN (VLAN) - VLANs are used to improve local network security and isolation. VLANs are recommended for administering the appliance; otherwise, use VNICs.

• Virtual Network Interface Card (VNIC) - VNICs allow single or aggregated Ethernet datalinks to be split into multiple virtual (Ethernet) datalinks. VNICs can be optionally tagged with VLAN IDs, and can allow physical network port sharing in a cluster as described in Clustering Considerations for Networking.

• InfiniBand (IB) partitions - InfiniBand partitions connect to logically isolated IB fabric domains.

• Link Aggregation Control Protocol (LACP) - LACP is used to bundle multiple network devices such that they behave as one. This improves performance by increasing bandwidth and improves reliability by protecting from network port failure. The appliance must be connected to a switch that supports LACP and has enabled LACP for those ports.

Note:

VNIC-based and VLAN-based datalinks cannot share the same VLAN ID. The IEEE 802.3ad Link Aggregation standard does not explicitly support aggregations across multiple switches, but some vendors provide multi-switch support via proprietary extensions. If a switch configured with those extensions conforms to the IEEE standard and the extensions are transparent to the end-nodes, its use is supported with the appliance. If an issue is encountered, Oracle Support might require the issue to be reproduced on a single-switch configuration.

The following table describes settings that are available to configure datalinks.

Table 2-6 Datalink Properties

BUI Property	CLI Property	Description
Name	label	Use the defined custom name. For example: "internal", "external", "adminnet", and so on. The default value is "Untitled Datalink".
Speed	speed	Use the defined speed. Valid values are auto, 10, 100, 1000 and 10000, representing autonegotiation, forced 10Mbit/sec, forced 100Mbit/sec, forced 1Gbit/sec and forced 10Gbit/sec. Speed and duplex must be either both forced to specific values or both set to autonegotiate. Not all networking devices support forcing to all possible speed/duplex combinations. Disabling autonegotiation is strongly discouraged. However, if the switch has autonegotiation disabled, it might be necessary to force speed and duplex to ensure the datalink runs at the expected speed and duplex.
Duplex	duplex	Use the defined transmission direction. Valid CLI values are auto, half, and full, representing autonegotiation, half-duplex and full-duplex respectively. Speed and duplex must be either both forced to specific values or both set to autonegotiate. See more information in the description of the speed property earlier.
VLAN	class=vlan	Use VLAN headers.
VLAN ID	id	Use the defined VLAN identifier; optional for VNICs.
VNIC	class=vnic	Use a VNIC.
MTU	mtu	Use the defined maximum transmission unit (MTU) size. The default MTU is 1500 bytes. Specify a lower MTU (minimum 1280) to leave packet headroom (for example, for tunneling protocols). Specify a larger MTU (maximum 9000) to improve network performance. All systems and switches on the same LAN must be configured with the chosen MTU. After the MTU value is set and the new network configuration is committed to the system, you can return to the network screen and view the datalink status to see the exact MTU value in bytes that was selected. Note that a VLAN or VNIC cannot be configured with an MTU value larger than that of the underlying datalink.
LACP Aggregation	aggregation	Use multiple network device LACP aggregation.
LACP Policy	policy	Use the defined LACP policy for selecting an outbound port. L2 hashes the source and destination MAC address; L3 uses the source and destination IP address; L4 uses the source and destination transport level port.
LACP Mode	mode	Use the defined LACP communication mode. Active mode will send and receive LACP messages to negotiate connections and monitor the link status. Passive mode will listen for LACP messages only. Off mode will use the aggregated link but not detect link failure or switch configuration changes. Some network switch configurations, including Cisco EtherChannel, do not use the LACP protocol: The LACP mode should be set to off when using non-LACP aggregation in your network.
LACP Timer	timer	Use the defined interval between LACP messages for Active mode.
IB Partition	partition	Use IB Partitions.
Partition Key	pkey	Use the partition (fabric domain) in which the underlying port device is a member. The partition key is found on and configured by the subnet manager. The partition key can be defined before configuring the subnet manager but the datalink will remain "down" until the subnet partition has been configured with the port GUID as a member. Keep partition membership for HCA ports consistent with IPMP Configuration and Appliance Cluster Configuration rules on the subnet manager.
IB Link Mode	linkmode	Use the defined IB link mode. IPoIB provides two link modes: Connected (the default) and Unreliable Datagram. Connected mode is recommended over Unreliable Datagram. Use Unreliable Datagram only when technically required. Connected mode provides higher throughput than Unreliable Datagram mode. Connected mode uses an MTU of 65520. Unreliable Datagram mode uses an MTU of 2044. Connected mode uses IB queue pairs and dedicates a local queue pair to communicate with a dedicated remote queue pair. Unreliable Datagram allows a local queue pair to communicate with multiple other queue pairs on any host, and messages are communicated unacknowledged at the IB layer.
Large Receive Offload (LRO)	lro	Use large receive offload (LRO) (on). Default is off. LRO merges successive incoming packets into a single packet before the packets are delivered to the IP layer. Enabling this feature might provide performance benefits when using smaller MTU sizes. LRO does not apply to IPv6 interfaces that are built on top of datalinks with LRO enabled.