Using automatic configuration
With the automatic configuration feature, the device can automatically obtain a set of configuration
settings from some servers when it starts up without a configuration file. This feature simplifies network
configuration, facilitates centralized management, and reduces maintenance workload.
Understanding automatic configuration
The automatic configuration feature requires the cooperation of the following servers: a DHCP server, an
HTTP server, a TFTP server, and a DNS server, as shown in
Figure 51 Typical automatic configuration network diagram
When the device is powered on without a configuration file, it automatically starts the automatic
configuration process to try to obtain a set of configuration settings. If one attempt fails, the device waits
30 seconds, and then automatically starts the process again for another try. The device continues to
make attempts until it obtains a set of configuration settings. To stop the process, power off the device or
press Ctrl+D.
Overall automatic configuration process
As shown in
1.
The device selects an interface for automatic configuration. For more information, see
selection
2.
After finding an interface, the device enables the DHCP client on the interface and tries to obtain
a set of parameters for automatic configuration, which might include a temporary IP address, a
configuration file name, a TFTP server domain name, a TFTP server IP address, and a DNS server
IP address. For more information, see
3.
After obtaining automatic configuration parameters, the device tries to download a configuration
file from a TFTP server or an HTTP server. For more information, see
process."
Figure
52, the automatic configuration process includes the following steps:
process."
Figure
"Automatic-configuration parameter acquisition
196
51.
"Configuration file acquisition
"Interface
process."