Dell PowerEdge M420 Dell PowerConnect M8024-k User's Configuration Guide - Page 142
How is the Firmware Updated on the Stack?, What is Stacking Standby?, What is Nonstop Forwarding?
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How is the Firmware Updated on the Stack? When you add a new switch to a stack, the Stack Firmware Synchronization feature automatically synchronizes the firmware version with the version running on the stack master. The synchronization operation may result in either upgrade or downgrade of firmware on the mismatched stack member. Upgrading the firmware on a stack of switches is the same as upgrading the firmware on a single switch. After you download a new image by using the File Download page or copy command, the downloaded image is distributed to all the connected units of the stack. For more information about downloading and installing images, see "Managing Images and Files" on page 363. What is Stacking Standby? A Standby unit is preconfigured in the stack. If the current Master unit fails, the Standby unit becomes the Master unit. If no switch is pre-configured as the Standby unit, the software automatically selects a Standby unit from the existing stack units. When the failed Master resumes normal operation, it joins the stack as a member (not a Master) if the new Master unit has already been elected. The Master unit copies its running configuration to the Standby unit whenever it changes (subject to some restrictions to reduce overhead). This enables the Standby unit to take over the stack operation with minimal interruption if the Master unit becomes unavailable. The running-config synchronization also occurs: • when you save the running configuration to the startup configuration on the Master unit. • when the backup unit changes. What is Nonstop Forwarding? Networking devices are often described in terms of three semi-independent functions called the forwarding plane, the control plane, and the management plane. The forwarding plane forwards data packets and is implemented in hardware. The control plane is the set of protocols that determine how the forwarding plane should forward packets, deciding which data packets are allowed to be forwarded and where they should go. Application software on the Management Unit acts as the control plane. The 142 Managing a Switch Stack
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1,196
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1,197
-
1,198
-
1,199
-
1,200
-
1,201
-
1,202
-
1,203
-
1,204
-
1,205
-
1,206
-
1,207
-
1,208
-
1,209
-
1,210
-
1,211
-
1,212
-
1,213
-
1,214
-
1,215
-
1,216
-
1,217
-
1,218
-
1,219
-
1,220
-
1,221
-
1,222
-
1,223
-
1,224
-
1,225
-
1,226
-
1,227
-
1,228
-
1,229
-
1,230
-
1,231
-
1,232
-
1,233
-
1,234
-
1,235
-
1,236
-
1,237
-
1,238
-
1,239
-
1,240
-
1,241
-
1,242
-
1,243
-
1,244
-
1,245
-
1,246