Fast Etherchannel Not Functioning

[Phobos1821]

Hello,

I currnetly have a Dell Powervault 715N Nas w/2 Intel PRO NIC's, connected to a Cisco 2950XL Switch on ports 6 & 7. Currently the Powervault & the Switch are configured for FastEtherchannel configuration, but it is not working.

After examining our network performance, i found out that the link on Port 7 averages about 1.3Mb/s, while the link on port 6 averages 300K/s.

This is not load balancing.

I dont know why it's not working, it's pretty simple. Here is my quick config if you can spot anything to help me out.

Thanks.
----------
interface FastEthernet0/6
duplex full
speed 100
port group 2

interface FastEthernet0/7
duplex full
speed 100
port group 2

 

[Piass]

I would suggest that you try to find out how exactly etherchannel works on the 2900XL switches. It never just load balances 50/50. It uses a hash algorithm based on one of a few variables. I know that on the 6500 it can be configured to use source and destination MAC addresses, or IP addresses, or port numbers when it's working out the algorithm. For example, if you had a lot of traffic going from one server to another server on the same VLAN, the source and destination MAC addresses would always be the same. Therefore, the algorithm would always give the same result, which would be to send the traffic down one link in the etherchannel.

Have a search on CCO and see what you can find. Also, have a think about traffic patterns on your network.

 

[Phobos1821]

The only option i have with the 2900XL switches are Source, and Destination channeling. By default, source is selected. Even though is is not 50/50, i dont believe the 'Load Balanced' link is helping out any trafic if the split is around 2.5mb/600k.

 

[Phobos1821]

Yes, another Point is that the downloads only happen on this machine between one computer.

x.x.x.7 -> x.x.x.95

So source routing wont really help me, since its from the same Machine. Neither destination as well i suspose. Is there any way to get a good load balance (downloading)?

 

[rburke]

Do you absolutely need the two lines attached at once? You could just use one as the redundant line in case something happens to the primary line. Since you said it is only moving at around 2.5Mb/s then one port should easilty be able to handle that traffic. I'm not sure what the software in the Dell supports, but if it supports this type of topology I think that is your best shot.

Let me know if this helps...

Burke

 

[jlwass]

I took a Cisco class last year and the instructor said you won't see a 50/50 split with FastEtherchannel. It is more like 85/15 split. I have some systems where we are using four ports and see a 75/15/5/5 split. Also, you won't get a connection at 400BaseT. The Fast EtherChannel was explained will guaranty a 100BaseT speed rather than a total of the four.

Jeff

 

[baddos]

When I do etherchannel for server, I do it for a redundancy purpose. If you want more speed, go 1gb.