How to troubleshoot ifgrp issues in 7-Mode/ONTAP 9.1 and prior
Applies to
- ONTAP 9
- Data ONTAP 8 7-mode
- Data ONTAP 7
Description
- Link Aggregation, also referred to as “port trunking” “link bundling” “ethernet/network/NIC bonding” and “NIC teaming”, is a method of combining multiple network connections in parallel to increase throughput beyond the level that a single connection can sustain, and/or a method of providing redundancy in-case one or more links in the Link Aggregation fail.
- In Data ONTAP, a Link Aggregation is referred to as an “ifgrp” and allows for the following options:
- Single mode:
- This is an active/passive link. While more than two physical interfaces can be added to the ifgrp, in this mode only one link will be active at any given time.
- This option provides for a non-disruptive failover of the physical links within the ifgrp.
- This configuration requires no specific switch configuration/s to function.
- This function is not recommended for Clustered ONTAP.
- Instead it is recommended to use failover groups.
- Multimode:
- This option is more specifically referred to as “static multimode” and provides for the active link aggregation of interfaces to increase the amount of total potential bandwidth of the overall ifgrp however the connection to anyone client will not exceed the maximum throughput of any one link in the ifgrp (meaning that if 2 1g interfaces are used, the maximum throughput to any one client is 1g).
- Multimode interfaces can detect only a loss of link, not loss of client connectivity or switch misconfigurations that might result in negative performance or connectivity failure.
- Multimode may recover from link failures by redirecting traffic onto the surviving interfaces; however, there must be at least one physical interface remaining in the ifgrp with an active link. Switch configuration is required to use this option.
- LACP:
- This option, also referred to as “dynamic multimode”, allows for group membership communication to the connected switch.
- This allows for the ability for the Storage Controller (Node) to report inability to communicate with the switch as well as the Multimode ability to detect link failure. Data ONTAP implements LACP in nonconfigurable active mode that works well with switches that are configured in either active or passive mode.
- Data ONTAP implements the long and short LACP timers for use with nonconfigurable values (3 seconds and 90 seconds).
- Switch configuration is required to use this option.
- Single mode: