Sending DHCP client option 121 'Classless Static Route' request on WAN with Advanced Request options

NathanPH · Jul 19, 2022, 5:10 PM

So I just recently had FTTP installed and I'm trying to replace the ISP supplied router with my pfSense box connected directly into the Fibre ONT. I inserted a switch and ran Wireshark between the ISP provided routers WAN port the and ONT which has allowed me to capture the DHCP request options the ISP router sends, along with the WAN MAC address, identifiers and other details.

I've been putting these into the Advanced section under the WAN interface DHCP settings to make the requests pfSense sends identical. I've got pretty much everything matched up now by setting the Send options and Request options, but I can't seem to get the DHCP Option 55 Paramater 121 (Classless Static Route) request to work.

If I put 'classless-static-route' in the Request options box then pfsense doesn't send the Option 55 Paramater request list at all, I have tried multiple different spellings and been searching the web for a while but can't find a solution.

I think it may be the spelling or that I am putting something in wrong, Does it have a different alias/name or something I should be using instead under the Request options field for this?

At the moment I have the following under the Request options and these all work/are sent as expected:

subnet-mask, routers, domain-name-servers, ntp-servers, dhcp-renewal-time, dhcp-rebinding-time

If I don't specify any advanced request options then pfSense actually sends Option 55 Paramater 121 by default, but of course once I specify any manual request options then it sends only the ones I specify - meaning I have to get it back somehow as the ISP requires it.

Any help to get the 'Classless Static Route' request sending would be greatly appreciated, I have spent a number of hours trying to work this out on my own and looking for solutions online.

Thank you.