This counter tallies the total bytes received across all ports in a group from packets that contained errors and were not addressed to the IN3000, i.e. corrupted pass-through traffic. A steady rise here indicates a physical-layer problem somewhere among the hosts wired into that group rather than an issue with the IN3000's own management traffic. An admin narrowing down a segment-wide error problem would check whether this counter is elevated on group 3 before inspecting individual ports within that group.