NIC teaming: Is it possible to get 200mbps?

[Eric Smith_19]

I have a set of NC7781s in a DL360 G4 teamed with the following configuration:

load balance
balance with MAC address
switch assisted load balancing

My understanding of the Cisco port channeling implemenation is that it would only be possible to get 200mbps bandwidth if I am pulling data from sources that have different MAC addresses. So in theory if I have a subnetted network, any transfers that come from outside the local network will come from the MAC address of my VLAN router correct? Doesn't this limit the throughput to 100Mbps in most situations (which is actually what I see)? If there is a configuration that yields 200mbps no matter what the scenario does anyone know what it is? Otherwise I'll probably purchase a GIG-E -> GBIC adapter and setup gigabit over ethernet. Doesn't seem necessary in my situation (backups) as I only have 2 tape drives and can only stream data to tape from 2 different sources at time.

Any feedback is greatly appreciated.

[Steve Kadish]

Eric,

I have teamed NICs on several Proliant servers connected to Cisco switches. I use "Switch Assisted Load Balancing," but do not balance by MAC Address.

On the switch, I create a port-channel interface, and assign both ports to it, as follows:

interface Port-channel3
switchport

interface GigabitEthernet2/15
spanning-tree portfast
channel-group 3 mode on

interface GigabitEthernet2/16
spanning-tree portfast
channel-group 3 mode on

From the configuration I get 2GB pipes and the same will apply to 100MB links.

Good luck,
- Steve

[Eric Smith_19]

I do receive a connection that is labeled as "200mbps" however when looking at the actual throughput either via MRTG or other monitoring devices I'm only getting 100mbps on one specific NIC. The other NIC is neither sending or receiving traffic. Do you balance by IP address? Also have you literally measured the throughput and seen data traversing both NICs?

Thanks for the response!

[Mike Strako]

When NIC's are teamed, what you see is total bandwidth of combined NICs, but what actually occors in a switch-assisted MAC or IP setup, 1 NIC IS recieving and the other is transmitting (minus heart-beat action).

[Eric Smith_19]

Do you know if this is documented somewhere? I've looked throughout the help files and documentation but to no avail.

[Mike Strako]

I have a link here that describes what I was talking about - I know the frustration. :-) I too was looking at some bandwidth issues at the time before we went Gig in the NICs. Look at the NLB and ALB, it's an interesting read.

http://support.intel.com/support/network/sb/CS-009747.htm


Mike.

[Eric Smith_19]

I'm confused; Why did you send me a link to the Intel implemenation of link aggregation / load balancing? The NICs in question are both NC7781 HP adapters.

Thanks,
Eric

[Mike Strako]

I was showing basic documentation you requested on how the communications occor on teamed NICs with different protocols.

[Eric Smith_19]

So you're assuming then the HP teaming protocol works the same as intel?