Cisco Cisco SG500-52PP 52-port Gigabit Max PoE+ Stackable Managed Switch 维护手册

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页码 653
Administration: File Management
Auto Configuration/Image Update via DHCP
65
Cisco 500 Series Stackable Managed Switch Administration Guide
4
Auto Configuration/Image Update via DHCPv6 is triggered when the following 
conditions are fulfilled: 
When a DHCPv6 server sends information to the device. This occurs in the 
following cases:
-
When an IPv6-enabled interface is defined as a DHCPv6 stateless 
configuration client. 
-
When DHCPv6 messages are received from the server (for example, 
when you press the Restart button on IPv6 Interfaces page, 
-
When DHCPv6 information is refreshed by the device. 
-
After rebooting the device when stateless DHCPv6 client is enabled.
When the DHCPv6 server packets contain the configuration filename 
option. 
The Auto Image Update process is triggered when an indirect image file 
name is provided by the DHCP server or a backup indirect image file name 
has been configured. Indirect means that this is not the image itself, but 
rather a file that holds the path name to the image.
Auto Configuration Image Update in a Stack
The current master of a stack is responsible for the Auto Configuration/Image 
Update of the whole stack. For auto configuration, the new configuration file is 
downloaded to the master unit. For auto image update, the new image is saved to 
the non-active image of the master unit. After the stack is rebooted, the new image 
is copied to the units of the stack.
Ensuring Correct Performance
To ensure that the Auto Configuration/Image Update feature works correctly, note 
the following:
A configuration file that is placed on the TFTP/SCP server must match the 
form and format requirements of the supported configuration file. The form 
and format of the file are checked, but the validity of the configuration 
parameters is not checked prior to loading it to the Startup Configuration.
In IPv4, to ensure that a device downloads the configuration and images file 
as intended during the Auto Configuration/Image Update process, it is 
recommended that the device is always assigned the same IP address.