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.
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 article1, 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.