I tried to run NSD 4.3.1 on a machine (Debian 10.4), which uses bonding for LACP. Starting NSD fails with this error message:

setsockopt(..., SO_BINDTODEVICE, ..., ...) failed: No such device

Running it on a pretty much identical setup with plain interfaces works.

Best guess so far is, that SO_BINDTODEVICE introduced with NSD 4.3.0 seems to not play well with virtual devices.

Is it possible to detect such virtual interfaces automatically and subsequently not apply this socket option to avoid startup failures?

Furthermore, the option to disable this functionality for config files (bindtodevice: <yes or no>) seems broken. It is considered invalid by nsd-checkconf. Setting it prevents NSD from being started as well.