Auto-negotiation

See Auto-negotiation for a general discussion on network negotiations.

On AIX®, you can check the link using SMIT. In SMIT, go to Devices > Communication > Ethernet Adapter > Adapter > Change / Show Characteristics of an Ethernet Adapter. Select the network interface. The link speed and mode configuration is displayed in the Media Speed field.

Alternatively, you can issue the following commands:

   $ lsparent -C -k ent
   ent0 Available 40-58 IBM 10/100 Mbps Ethernet PCI Adapter (23100020)
   
   $ lsattr -E -l ent0 -a media_speed
   media_speed Auto_Negotiation Media Speed True
   

To find out the actual negotiated speed and duplex, issue the following command:

   $ netstat -v ent0 | grep Media
   Media Speed Selected: Auto negotiation
   Media Speed Running: 100 Mbps Full Duplex
   

If the auto-negotiation failed, you can set the NIC from SMIT or by issuing the following commands:

   
   $ chdev  -l ent0 -a media_speed=100_Full_Duplex -P
   ent0 changed
   
   reboot