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Deploying the Dell Force10 MXL into a Cisco Nexus Network Environment

Appendix B: Basic Terminology

Bridging

Bridging—commonly called switching—is frame-by-frame layer-2 forwarding of Ethernet traffic with

forwarding decisions generally based on each frame’s source and destination MAC address. A simple

bridge has three available actions to perform on received traffic—filter, forward, or flood. An Ethernet

bridge is very simple and relies on bridging protocols like spanning-tree to not send data frames in a

loop, causing a storm.

Channel Group

See LAG.

CLI

Command Line Interface (CLI) is the text-based console interface that is used for entering management

and configuration commands into devices like the Dell Force10 MXL switch. The MXL’s CLI can be

accessed via telnet, SSH, an externally-accessible serial connection, and also from the CMC’s CLI.

CMC

Chassis Management Controller (CMC) is the embedded management interface of the Dell PowerEdge™

M1000e blade server chassis. Among other functions, the CMC provides network and console access to

installed IO modules including the Dell Force10 MXL switch.

Filter, Flood, Forward

Data frames received by Ethernet switches may be filtered (meaning discarded or dropped) according

to defined behavior, automatic protocols, or administrative configuration; flooded (meaning sent out

all other links) if the data frame’s destination MAC address is unknown; or forwarded (meaning sent to

one other link) if the destination MAC address is already learned. A destination for a MAC address may

be manually configured on a link’s interface; but, most MAC address destinations are learned

dynamically based on source MAC addresses of already received data frames—when a bridge receives a

data frame, it remembers the source MAC address of the frame on the received link for five minutes

and will then selectively forward data frames destined for that MAC address over that link as a learned

destination.

IOM

IO module (IOM) refers to the modules at the rear of the Dell PowerEdge M1000e chassis that will

receive and transmit I/O (Ethernet, FC, Infiniband, etc.) from the blade servers located at the front of

the chassis. The Dell Force10 MXL switch is as an IOM for the M1000e blade server chassis.

LACP

Link Aggregation Control Protocol (LACP) is the protocol used to ensure that the multiple links in a LAG

do not form loops due to misconfiguration or device misbehavior. It is recommended practice to always

use LACP on configured LAGs.