Q&A: Etherchannel Throughput

New Q&A Series

I’m starting a new series here to go through some the the exam topics in a little more detail. This is the kind content you’ll find in the interactive Cram Cards and the kind of detail required to be successful in your CCNP studies. If you have any input or questions related to what you see below, feel free to leave a comment at the bottom. I’m looking forward to seeing where this goes.


If four Fast Ethernet ports are bundled into an EtherChannel, what is the maximum throughput provided by the EtherChannel?


800 Mbs

Each FastEthernet connection supports 100 Mbs, but because Catalyst switches can operate in a full-duplex manner, that theoretical throughput doubles to 200 Mbs (100 Mbs in each direction simultaneously). Now combine four of those links into a single logical EtherChannel and that is multiplied by 4 to 800 Mbs.

  • 1 Fast Ethernet link = 200Mbs (100Mbs Tx, 100Mbs Rx)
  • 4x 200Mbs = 800Mbs

Keep in mind that this is all theory. These numbers would be hard to achieve in practice because of cabling limitations and imperfect EtherChannel load balancing algorithms. We’re talking about theoretical max throughput, but that’s exactly what Cisco refers to when they talk EtherChannel bundle bandwidth.

Author Aaron

Aaron knows networks. He's been involved in building and supporting world-class data networks for the past 10 years - from international cloud service providers to Fortune 50 data centers. Aaron consults independently and is focused on building the best training platform available.

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