Configuring Network Datalinks

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Network datalinks manage devices, and are used by interfaces. They support:

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 reliability (by protecting from network port failure); however, the appliance must be connected to a switch that supports LACP and has it enabled for those ports.
InfiniBand (IB) Partitions - InfiniBand partitions connect to logically isolated IB fabric domains.
Virtual LANs (VLANs) - VLANs are used to improve local network security and isolation. VLANs are recommended for administering the appliance; otherwise, use VNICs.
Virtual Network Interface Cards (VNICs) - 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. Step-by-step instructions can be found in Clustering Considerations for Networking below.

Note - VNIC-based and VLAN-based datalinks cannot share the same VLAN ID.

The IEEE802.3ad (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 may require it to be reproduced on a single-switch configuration.

The following datalink settings are available:

Table 17 Datalink Settings

Property	Description
Name	Use the defined custom name. For example: "internal", "external", "adminnet", etc.
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 may be necessary to force speed (and duplex) to ensure the datalink runs at the expected speed and duplex.
Duplex	Use the defined transmission direction. Valid CLI values are auto, half, and full, representing autonegotiation, half- and full-duplex respectively. Speed and duplex must be either both forced to specific values or both set to autonegotiate.
VLAN	Use VLAN headers.
VLAN ID	Use the defined VLAN identifier; optional for VNICs.
VNIC	Use a VNIC.
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	Use multiple network device LACP aggregation.
LACP 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	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	Use the defined interval between LACP messages for Active mode.
IB Partition	Use IB Partitions.
Partition Key	Use the partition (fabric domain) in which the underlying port device is a member. The partition key (pkey) is found on and configured by the subnet manager. The pkey may be defined before configuring the subnet manager but the datalink will remain "down" until the subnet partition has been properly configured with the port GUID as a member. It is important to keep partition membership for HCA ports consistent with IPMP Configuration and Appliance Cluster Configuration rules on the subnet manager.
IB Link Mode	Use the defined IB Link Mode. IPoIB provides two link modes: Connected (the default) and Unreliable Datagram. Connected mode provides higher throughput and is recommended over Unreliable Datagram. Use Unreliable Datagram only if technically required. Connected mode uses IB queue pairs and dedicates a local queue pair to communicate with a dedicated remote queue pair. Connected mode uses an MTU of 65520 and provides higher throughput than Unreliable Datagram. Unreliable Datagram lets a local queue pair communicate with multiple other queue pairs on any host and messages are communicated unacknowledged at the IB layer. Unreliable Datagram mode uses an MTU of 2044 and yields a lower throughput rate.