Port-Channel Load-Balance Question

[andres.lara]

We have a Bridgehead backup system and a DataDomain archive system connected to a Cisco 3750-X.  On the switch, the Bridgehead system has a 6 port GbE port-channel group and the the DataDomain has a 4 port GbE port-channel group. 

Each of the systems are configured, though some Broadcom suite, to bundle those ports together into 1 "virtual" interface with 1 IP address and 1 MAC Address.  When these systems communicate with each other they communicate directly so it is always Source IP BH to Destination IP DD (Bridgehead > DataDomain) and vice-versa.

Our current load-balancing method, which is "src-dst-ip", is resulting in primarly one GbE port being used.  Do any of you see a better load-balancing method which we could use? Thank you all in advance for any suggestions or assistance you may offer.

[Peter Paluch]

Hi Andres,

Unless your switch supports src-dst-port which would load balance based on L4 ports, I do not think this issue can be solved by choosing a different load balancing method. You see, the problem is that the data flows always use a very limited, if not constant, source/destination address pairs.

Is there any possibility of configuring either device with a couple of secondary addresses and have those devices contact themselves using a randomly chosen source/destination IP address? If they support DNS and can refer to each other using hostnames instead of IP addresses, one possible solution would be to have the hostname in the DNS associated with multiple IP addresses, so every time a device would resolve the hostname, it would get a different IP address, facilitating the load balancing.

Best regards,

Peter