Brocade 6910 Ethernet Access Switch Diagnostic Guide (Supporting R2.2.0.0) - Manual (Page 26)

16 Brocade 6910 Ethernet Access Switch Diagnostic Guide
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DRAFT: BROCADE CONFIDENTIAL
Ethernet diagnostics
The packet loss happens when both devices are transmitting at the same time, and may happen
even when the link is used, from the user's perspective, in one direction only. A Transmission
Control Protocol (TCP) stream requires that all packets sent be acknowledged by the receiving
device, even if actual data is sent in one direction only. Packet collisions may occur with
acknowledgement packets traveling in the other direction.
Because the full-duplex device does not expect incoming frames to be truncated by collision
detection, the device reports Frame Check Sequence (FCS) errors. The combination of late
collisions reported at the half-duplex end, and FCS errors reported by the full-duplex end, can
indicate a duplex mismatch.
Ethernet show commands
This section describes the show commands that display information about Ethernet interfaces.
show interfaces brief
Syntax: show interfaces brief
This command displays a summary of the information provided in the show interfaces command.
Command output resembles the following example.
Console# show interfaces brief
Interface Name Status PVID Pri Speed/Duplex Type Trunk
--------- ------------------ -------- ---- --- ------------- ------------ -----
Eth 1/ 1 Up 1 0 Auto-100full 1000T None
Eth 1/ 2 Down 1 0 Auto 1000Base SFP None
show interfaces counters ethernet
Syntax: show interfaces counters ethernet unit/port
unit - Unit identifier. (Range: 1)
port - Port number. (Range: 1-12)
This command displays statistics about a specific Ethernet interface, as shown in the following
example.
Console# show interfaces counters ethernet 1/1
Ethernet 1/ 1
===== IF table Stats =====
1562954 Octets Input
5265175 Octets Output
5389 Unicast Input
6254 Unicast Output
0 Discard Input
0 Discard Output
0 Error Input
0 Error Output
0 Unknown Protos Input
0 QLen Output
===== Extended Iftable Stats =====
10446 Multi-cast Input
11128 Multi-cast Output
313 Broadcast Input
2 Broadcast Output
===== Ether-like Stats =====
0 Alignment Errors