Operating rules for IP preserve
When ip preserve
is entered
as the last line in a configuration file stored on a TFTP server:
If the switch’s current IP address for VLAN 1 was not configured by DHCP/ Bootp, IP Preserve retains the switch’s current IP address, subnet mask, and IP gateway address when the switch downloads the file and reboots. The switch adopts all other configuration parameters in the configuration file into the startup-config file.
If the switch’s current IP addressing for VLAN 1 is from a DHCP server, IP Preserve is suspended. In this case, whatever IP addressing the configuration file specifies is implemented when the switch downloads the file and reboots. If the file includes DHCP/Bootp as the IP addressing source for VLAN 1, the switch will configure itself accordingly and use DHCP/ Bootp. If instead, the file includes a dedicated IP address and subnet mask for VLAN 1 and a specific gateway IP address, then the switch will implement these settings in the startup-config file.
The
ip preserve
statement does not appear inshow config
listings. To verify IP Preserve in a configuration file, open the file in a text editor and view the last line.