Configuring an EtherChannel

Use this 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 you want on your EtherChannel and press Enter.
   If you are planning to use EtherChannel backup, do not select the adapter that you plan to use for the backup at this point.

   Note: The Available Network Adapters displays all Ethernet adapters. If you select an Ethernet adapter that is already being used (has an interface defined), you will get an error message. You first need to detach this interface if you want to use it.
4. Enter the information in the fields according to the following guidelines:
   • Parent Adapter: Provides information of an EtherChannel's parent device (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 parent adapter's name (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 should see all primary adapters that you are using in your EtherChannel. You selected these adapters in the previous step.
   • Enable Alternate Address: This field is optional. Setting this to yes will enable you to specify a MAC address that you want the EtherChannel to use. If you set this option to no, the EtherChannel will use 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 here. The address you specify must start with 0x and be a 12-digit hexadecimal address (for example, 0x001122334455).
   • Enable Gigabit Ethernet Jumbo Frames: This field is optional. In order to use this, your switch must support jumbo frames. This will only work with a Standard Ethernet (en) interface, not an IEEE 802.3 (et) interface. Set this to yes if you want to enable it.
   • Mode: You can choose from the following modes:
     • standard: In this mode the EtherChannel uses an algorithm to choose which adapter it will send the packets out on. The algorithm consists of taking a data value, dividing it by the number of adapters in the EtherChannel, and using the remainder (using the modulus operator) to identify the outgoing link. The Hash Mode value determines which data value is fed into this algorithm (see the Hash Mode attribute for an explanation of the different hash modes). For example, if the Hash Mode is standard, it will use the packet's destination IP address. If this is 10.10.10.11 and there are 2 adapters in the EtherChannel, (1 / 2) = 0 with remainder 1, so the second adapter is used (the adapters are numbered starting from 0). The adapters are numbered in the order they are listed in the SMIT menu. This is the default operation mode.
     • round_robin: In this mode the EtherChannel will rotate through the adapters, giving each adapter one packet before repeating. The packets may be sent out in a slightly different order than they were given to the EtherChannel, but it will make 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, leave the Hash Mode value as default.
     • netif_backup: To enable Network Interface Backup Mode, you can configure multiple adapters in the primary EtherChannel and a backup adapter. For more information, see Configuring Network Interface Backup.
     • 8023ad: This options enables the use of the IEEE 802.3ad Link Aggregation Control Protocol (LACP) for automatic link aggregation. For more details about this feature, see IEEE 802.3ad Link Aggregation configuration.
   • IEEE 802.3ad Interval: You can 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.
       Note: The interval value is only used when EtherChannel is operating in IEEE 802.3ad mode. Otherwise, the value is ignored.
       Note: AIX honors both long and short interval request from its partner.
   • Hash Mode: Choose from the following hash modes, which will determine the data value that will be 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. This mode guarantees packets are sent out over the EtherChannel in the order they were received, but it may 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 will be used. If the packet is not IP traffic, the last byte of the destination MAC address will be 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 will be used. If the packet is not IP traffic, the last byte of the destination MAC address is used.
     • src_dst_port: The source and destination UDP or TCP port values of the packet is used to determine the outgoing adapter (specifically, the source and destination ports are added and then divided by two before being fed into 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 will be 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 the adapter that you want to use as your EtherChannel backup.
   • Internet Address to Ping: This field is optional and only takes effect if you are running Network Interface Backup mode or if you have one or more adapters in the EtherChannel and a backup adapter. The EtherChannel will ping the IP address or host name that you specify here. If the EtherChannel is unable to ping this address for the number of times specified in the Number of Retries field and in the intervals specified in the Retry Timeout field, the EtherChannel will switch adapters.
     Note: Monitoring pings in the multipath routing environment is not supported. But 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 have set an Internet Address to Ping.
   • Retry Timeout: Enter the number of seconds between the times when the EtherChannel will ping the Internet Address to Ping. The default is one second. This field is optional and valid only if you have set an Internet Address to Ping.
5. Press Enter after changing the desired fields to create the EtherChannel.
6. Configure IP over the newly-created EtherChannel device by typing smitty chinet at the command line.
7. Select your new EtherChannel interface from the list.
8. Fill in all of the required fields and press Enter.