Broadcom Generic Link Aggregation

[jdavis1]

Does anyone know if the 3Com "Port Trunk" link aggregation is compatible with Generic Link Aggregation on NICs with the Broadcom chipset? If you can't answer this, can you tell me if 3Com's "Port Trunk" link aggregation is compatible with Cisco's EtherChannel link aggregation?

Thanks

 

[TimRegester]

3Com uses the 802.3ad Link Aggregation standard using a protocol known as LACP (Link Aggregation Control Protocol).

The standard is based on Etherchannel since Cisco brought it to the IEEE standards board, but as I recall it is subtley different from Etherchannel to allow better vendor switch interoperability. I gather later versions of Catalyst software support it, but probably not on all switches.

On version 3.0 of the code for the 4900 under the bridge menu there was an option called Link Aggregation. This is the command used to connect to teamed nics or aggregate a link to another 802.3ad compliant switch.

Good luck

 

[jdavis1]

Thanks for the reply. These switches are SuperStack 3300's, which were designed and built before LACP came about. Did that capability get added to that switch in later software releases?

Yes, the newer versions of Cisco IOS and CatOS all support 802.3AD. I'm much more familiar with the Cisco switches than the 3Com switches. The reason that I asked whether or not it was compatible with the Cisco trunking is that I reasoned that if it wasn't, then it wouldn't be compatible with Broadcom's generic link aggregation.

a) Broadcom generic link aggregation is compatible with Cisco Etherchannel
b) Cisco Etherchannel is incompatible with 3Com port-trunk link aggregateion
c) Therefore, Broadcom link aggregation is incompatible with 3Com port-trunk link aggregation.

Not a completely sound bit of logic (Broadcom could sense the type of switch that it is connected to, but not likely).