From what I understand, the 2960 has a limit of 6 EtherChannels per switch stack with the lan base image. Does anyone know if the Etherchannel limitation due to physical bandwidth, or software? I really want to increase this number, and I doubt it will affect the _overall_ bandwidth through the switch. Is the only solution to purchase a different switch?
6 only , we ran into this awhile ago and ended up replacing it with a 3560 for more etherchannel
Most likely the limitation is due to resource allocation. Every time you create an EtherChannel, the switch has to allocate resources (memory) to support the port grouping. Since most of the lower end switches are fixed configuration types, you will not have an option to increase the memory. Also, on these platforms, the I/O memory size is also fixed. A fragment of I/O memory will be used for EtherChannels. Hence, it is not advisable to have more than 6 EtherChannels on the hardware. The system could let you configure more than 6 EtherChannels at a time but if the system does not have enough memory to allocate to new EtherChannels, it will suspend some of the EtherChannels to allocate the memory to other processes (interface buffers).
Hope this helps.
the config guide says try not to configure more then 6 etherchannel. So it seems that you can configure more than 6 but you should not. I am assuming this is due to harware limitation.
From the config guide:
EtherChannel Configuration Guidelines
If improperly configured, some EtherChannel ports are automatically disabled to avoid network loops and other problems. Follow these guidelines to avoid configuration problems:
•Do not try to configure more than 6 EtherChannels on the switch.
•Configure a PAgP EtherChannel with up to eight Ethernet ports of the same type.
•Configure a LACP EtherChannel with up to16 Ethernet ports of the same type. Up to eight ports can be active, and up to eight ports can be in standby mode.
Here the config guide: