DD-WRT Fails Silently with Invalid DHCP Characters

23 August 2020

For a very long time I have been baffled by how the DHCP server of my DD-WRT router would crash whenever I added staic DHCP leases.

Screenshot of DD-WRT DHCP config section

Until I finally realised that the set of valid DHCP characters is very limited; and when one has been entered, DD-WRT's DHCP server (at the time of writing) would just silently fail.

What are the valid characters?

According to this article[1], they are:

Letters (A - Z) and Numbers (0 - 9) and the only other character that can be used is the hyphen (-). The other special non-alpha numeric characters CANNOT be used, which include the space, underscore, forward slash and back slash.

  1. https://support.crestron.com/app/answers/detail/a_id/4079/ ↩︎