IPv6 Management Features
IP Preserve for IPv6
; J8697A Configuration Editor; Created on release #K.13.01
time daylight-time-rule None
Figure 5-10. Example of How to Enter IP Preserve in a Configuration File
To download an IP Preserve configuration file to an IPv6-based switch, enter
the TFTP copy command as described in "TFTP File Transfers over IPv6" on
page 5-15 to copy the file as the new startup-config file on a switch.
When you download an IP Preserve configuration file, the following rules
To verify how IP Preserve was implemented in a switch, after the switch
reboots, enter the show run command. Figure 5-11 shows an example in which
all configurations settings have been copied into the startup-config file except
for the IPv6 address of VLAN 1 (2001:db8::214:c2ff:fe4c:e480) and the default
IPv6 gateway (2001:db8:0:7::5), which were retained.
Entering an ip preserve statement as the last line in a
configuration file stored on a TFTP server allows you to download
and execute the file as the startup-config file on an IPv6 switch.
When the switch reboots, the configuration settings in the
downloaded file are implemented without changing the IPv6
address and gateway assigned to the switch as shown in Figure
If the switch's current IPv6 address for VLAN 1 was statically configured
and not dynamically assigned by a DHCP/Bootp server, the switch reboots
and retains its current IPv6 address, subnet mask, and gateway address.
All other configuration settings in the downloaded configuration file are
If the switch's current IPv6 address for VLAN 1 was assigned from a DHCP
server and not statically configured, IP Preserve is suspended. The IPv6
addressing specified in the downloaded configuration file is implemented
when the switch copies the file and reboots.
If the downloaded file specifies DHCP/Bootp as the source for the
IPv6 address of VLAN 1, the switch uses the IPv6 address assigned by
the DHCP/Bootp server.
If the file specifies a dedicated IPv6 address and subnet mask for
VLAN 1 and a Gateway IPv6 address, the switch implements these
settings in the startup-config file.