bonding question on inbound packets

bradvan · 11-01-2013, 07:11 AM

I have a question about nic bonding as it relates to inbound traffic. If I have two 1Gb nics bonded with mode 802.3ad on two separate systems joined by a switch that is configured for that support, will I get an effective 2Gb connection between the two, or will it just be 1Gb? I'm asking because a Red Hat engineer mentioned to me that outbound traffic would go across both nics, but inbound would only come in on one. Did I just mishear him?

Thanks!

Ser Olmy · 11-01-2013, 07:21 AM

The good news is that both inbound and outbound traffic will be balanced across both links (802.3ad/802.3ax requires aggregation protocol support at both ends, so the switch will be balancing frames as well).

The bad news is that the algorithm uses MAC (or in some cases IP) addresses to select physical links, which means that packets to the same host will always be sent over the same link.

The effective bandwidth between two hosts will be that of a single link, which in your case is 1 Gb.

bradvan · 11-01-2013, 07:59 AM

Rats! This is what I thought. Thank you for the explanation.