Think about load balancing traffic to nodes that use redundant network interface cards (NICs)

SOL3009 says,

 

"The BIG-IP Controller is not compatible with redundant network interface cards (NICs).

 

...When the BIG-IP Controller load balances traffic, it tracks the last hop MAC address in order to send return traffic to the same MAC address. As a result, BIG-IP may continue to send traffic to the inactive NIC after a failover occurs between the two NICs." Click here

 

 

However, I think as follows.

 

 

When the server is on the response side like the load-balancing of HTTP, there is no problem. Even when the MAC address is not succeeded between the redundant NICs, BIG-IP forwards the request to the newly active NIC reacting on the Gratuitious ARP that the server issues. Of course, when the MAC address is succeeded between the redundant NICs, there is no problem.

 

 

The problem can occur due to the "Auto Last Hop" setting when BIG-IP is on the response side. When the MAC address is not succeeded between the redundant NICs and "Auto Last Hop" setting is enabled as the default setting, BIG-IP does continue to send traffic to the inactive NIC after a failover occurs between the two NICs as SOL3009 says. However, there is a workaround. That is, "Auto Last Hop" setting is disabled. (When the MAC address is succeeded between the redundant NICs, there is no problem.)

 

 

taro