[Kea-users] Error: Unable to override definition of option '121' in standard option space 'dhcp4'

[ldm at gmx.at]

Hi!

With recent Kea version 2.6.2 I am getting:
Error encountered: unable to override definition of option '121' in
standard option space 'dhcp4'.

Because my kea-dhcp4.conf relies on:

"option-def": [
  {
    "space": "dhcp4",
    "name": "rfc3442-classless-static-routes",
    "code": 121,
    "array": true,
    "type": "record",
    "record-types": "uint8,uint8,uint8,uint8,uint8,uint8,uint8,uint8"
  },
  {
    "space": "dhcp4",
    "name": "ms-classless-static-routes",
    "code": 249,
    "array": true,
    "type": "record",
    "record-types": "uint8,uint8,uint8,uint8,uint8,uint8,uint8,uint8"
  }
]

with some research I found issue #3074
https://gitlab.isc.org/isc-projects/kea/-/issues/3074


and a one year old merge request #2135
https://gitlab.isc.org/isc-projects/kea/-/merge_requests/2135

The issue states:

> While routes can be hand-mangled into the correct order and then
expressed as a string of hex bytes, this is onerous for DHCP
administrations and error-prone.

While I appreciate the option_classless_static_route.cc offers a new less
error-prone way of publishing static routes, I would still expect that I
can keep using the legacy old way of defining static classless routes in my
config. Especially since I want to use the same config on my failover kea
server that is still on Kea version 2.4.1 (stable) and can't be easily
upgraded. So the Kea version 2.6.2 apparently can't use the old way, and
the Kea version 2.4.1 (stable) can't use the new way of defining routes.


I found this https://kb.isc.org/docs/kea-configuration-sections-explained
documentation, but I am not sure how to use it. It seems more about
defining client classes than what I need.


Is there a way to get around the error "unable to override definition of
option '121' in standard option space 'dhcp4' "?


Best regards

Mark
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/kea-users/attachments/20250601/cd33b1a6/attachment.htm>