Dhcp Server Options - Cisco 300 Series Administration Manual

Administration: File Management
Auto Configuration via DHCP
Cisco Small Business 200, 300 and 500 Series Managed Switch Administration Guide (Internal Version)
Auto Configuration via DHCPv4 is triggered in the following cases:
• After reboot when an IP address is allocated or renewed dynamically (using
DHCPv4).
• Upon an explicit DHCPv4 renewal request and if the device and the server
are configured to do so.
• Upon automatic renewal of the DHCPv4 lease.
Auto Configuration 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 interface, which is IPv6 enabled, 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.

DHCP Server Options

DHCP messages might contain the configuration server name/address and the
configuration file name/path (these are optional options). These options are found
in the Offer message coming from the DHCPv4 servers and in the Information
Reply messages coming from DHCPv6 servers.
Backup information (configuration server name/address and configuration file
name/path) can be configured in the Auto Configuration page. This information is
used when the DHCPv4 message does not contain this information (but it is not
used by DHCPv6).
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