I'm wondering if is possible to configure a Cisco Router 881 from a file on a tftp instruct on a DHCP option. I know is possible to configure the wan port through DHCP by configuring "ip address dhcp" but what I search is there is a way to act as an Cable Modem CPE, dowload the configuration file from the DHCP and load it.

on the DHCP I've configure the following option as it will be for a CPE

filename "tftp://";

warning I'm not asking how to configure DHCP server on Cisco Router.

  • Which DHCP option for the file name? Commented Jul 18, 2013 at 9:48
  • I'm trying by adding the 'filename' line, option 66 tftp-server-name, option 67 bootfile-name on dhcpd.conf
    – cgasp
    Commented Jul 18, 2013 at 11:22

1 Answer 1


is there is a way to act as an Cable Modem CPE, download the configuration file from the DHCP [Option 67] and load it.

You are asking about Autoinstall in Cisco IOS:

  • Router (with blank NVRAM) pulls an address from DHCP
  • Router uses DHCP Options 3, 6, 66, 67, and 150 to reconfigure itself via TFTP

I also found a pretty good blog post on autoinstall

If you're looking for a tool to perform Autoinstall, check out freeztp; it's written in Python and uses a series of commands to set up configurable templates for IOS routers and switches.

Thank you for asking about this feature, I completely forgot it existed.

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