Configuring an EtherChannel

Complete the following procedure to configure an EtherChannel:

1. Type smitty etherchannel at the command line.
2. Select Add an EtherChannel/Link Aggregation from the list and press Enter.
3. Select the primary Ethernet adapters that are required for your EtherChannel and press Enter.
   If you plan to use EtherChannel backup, do not select the adapter that you plan to use for the backup.

   Note: The Available Network Adapters displays all Ethernet adapters. If you select an Ethernet adapter that is in use with an interface defined, you get an error message. Detach this interface to use it.
4. Enter the information in the following fields according to the following guidelines:

   Parent Adapter

   Provides information of the parent device of an EtherChannel. For example, when an EtherChannel belongs to a Shared Ethernet adapter. This field displays a value of NONE if the EtherChannel is not contained within another adapter (the default). If the EtherChannel is contained within another adapter, this field displays the name of the parent adapter. For example, ent6. This field is informational only and cannot be modified. The parent adapter option is available in AIX 5.3 and later.

   EtherChannel/Link Aggregation Adapters

   You must see all primary adapters that you use in your EtherChannel. You selected these adapters in the previous step.

   Enable Alternate Address

   This field is optional. If you set this option to yes, you can specify a MAC address that you want the EtherChannel to use. If you set this option to no, the EtherChannel uses the MAC address of the first adapter.

   Alternate Address

   If you set Enable Alternate Address to yes, specify the MAC address that you want to use. The address that you specify must start with 0x and it must be a 12-digit hexadecimal address. For example, 0x001122334455.

   Enable Gigabit Ethernet Jumbo Frames

   This field is optional. To use this option, your switch must support jumbo frames. This works only with a Standard Ethernet (en) interface, not an IEEE 802.3 (et) interface. Set this option to yes to enable it.

   Mode

   Choose from the following modes:

   standard

   In this mode, the EtherChannel by using an algorithm to choose which adapter it sends the packets out on. The algorithm consists of taking a data value, divide it by the number of adapters in the EtherChannel, and by using the remainder (by using the modulus operator) to identify the outgoing link. The Hash Mode value determines the data value that is fed into this algorithm. For a description of the different hash Moses, see Hash Mode attribute. For example, if the Hash Mode is standard, it uses the destination IP address of the packet. If the Hash Mode value is 10.10.10.11 and 2 adapters are in the EtherChannel, (1 / 2) = 0 with remainder 1, it uses the second adapter. The adapters are number starts from 0. The adapters are numbered in the order that they are listed in the SMIT menu. standard is the default operation mode.

   round_robin

   In this mode, the EtherChannel rotates through the adapters and gives each adapter one packet before you repeat. The packets might be sent out in a slightly different order than they were given to the EtherChannel, but it makes the best use of its bandwidth. It is an invalid combination to select this mode with a Hash Mode other than default. If you choose the round-robin mode, keep the Hash Mode value as default.

   netif_backup

   To enable Network Interface Backup Mode, you can configure one or more adapters in the primary EtherChannel and the backup EtherChannel. For more information, see Configuring Network Interface Backup.

   8023ad

   This option enables the use of the IEEE 802.3ad Link Aggregation Control Protocol (LACP) for automatic link aggregation. For more information about the feature, see IEEE 802.3ad Link Aggregation configuration page.

   IEEE 802.3ad Interval

   Choose from the following values:

   long

   This is the default value of the interval. When selected, the EtherChannel will request LACP packets from its partner at long interval value as specified by the protocol.

   short

   When selected, the EtherChannel will request LACP packets from its partner at short interval value as specified by the protocol.

   Notes:

   • The interval value is used only when EtherChannel is operating in IEEE 802.3ad mode. Else, the interval value is ignored.
   • AIX accepts both long and short interval request from its partner.

   Hash Mode

   Choose from the following hash modes, which determines the data value that is used by the algorithm to determine the outgoing adapter:

   default

   The destination IP address of the packet is used to determine the outgoing adapter. For non-IP traffic, such as ARP, the last byte of the destination MAC address is used to do the calculation. These mode guarantees packets are sent out over the EtherChannel in the order that they were received, but it might not make full use of the bandwidth.

   src_port

   The source UDP or TCP port value of the packet is used to determine the outgoing adapter. If the packet is not UDP or TCP traffic, the last byte of the destination IP address is used. If the packet is not IP traffic, the last byte of the destination MAC address is used.

   dst_port

   The destination UDP or TCP port value of the packet is used to determine the outgoing adapter. If the packet is not UDP or TCP traffic, the last byte of the destination IP is used. If the packet is not IP traffic, the last byte of the destination MAC address is used.

   src_dst_port

   The outgoing adapter is determined by using the source and destination UDP or TCP port values of the packet. Specifically, the source and destination ports are added and divided by two before you use in the algorithm. If the packet is not UDP or TCP traffic, the last byte of the destination IP is used. If the packet is not IP traffic, the last byte of the destination MAC address is used. This mode can give good packet distribution in most situations, both for clients and servers.

   Note: It is an invalid combination to select a Hash Mode other than default with a Mode of round_robin.

   To learn more about packet distribution and load balancing, see EtherChannel load-balancing options.

   Backup Adapter

   This field is optional. Enter a list of adapters that you want to use as EtherChannel backup.

   Internet Address to Ping

   This field is optional and takes effect only if you are running Network Interface Backup mode or if you have one or more adapters in EtherChannel and one or more adapters in the backup list. EtherChannel pings the IP address or host name that you specify. If EtherChannel is unable to ping the IP address for the number of times that are specified in the Number of Retries field and within the time interval that is specified in the Retry Timeout field, an EtherChannel changes over to the other adapters in the backup list. To reset this field such that the previously entered value for this option is removed, enter 0 as the Internet Address to Ping option value.

   Note: Monitoring pings in the multipath routing environment is not supported. As a workaround, use a separate address to ping for each EtherChannel and add a specific host route with the right EtherChannel interface name for the destination IP to the routing table.

   Number of Retries

   Enter the number of ping response failures that are allowed before the EtherChannel switches adapters. The default is three. This field is optional and valid only if you set an Internet Address to Ping.

   Retry Timeout

   Enter the number of seconds between the times when the EtherChannel pings the Internet Address to Ping. The default is one second. This field is optional and valid only if you set an Internet Address to Ping.

   MAC swap

   Select yes to enable MAC swap. MAC swap is allowed only on an EtherChannel in a Network Interface Backup configuration, one primary adapter and one backup adapter. If you enable the MAC swap, the backup adapter retains its MAC address and if failover occurs, this MAC is swapped to the primary adapter and the MAC of the primary adapter is swapped to the backup adapter. The default behavior, mac_swap=no is for the MAC of the primary adapter to be assigned to the backup adapter. In certain network configurations such as a VNIC/SR-IOV EtherChannel setup, this might result in duplicate packets that come on the inactive primary adapter after a failover. Enabling MAC swap avoids this situation. You are not allowed to configure an EtherChannel with MAC swap enabled unless there is exactly one primary adapter and exactly one backup adapter.

   LLDP packet processing mode

   This field is set to none by default. Set this field to replicate if the EtherChannel must send a modified Link Layer Discovery Protocol (LLDP) packet that is generated by the LLDP daemon to the underlying adapters of EtherChannel.

5. Press Enter after you change the required fields to create the EtherChannel.
6. Type smitty chinet at the command line to configure IP over the newly-created EtherChannel device.
7. Select your new EtherChannel interface from the list.
8. Complete the required fields and press Enter.