On Mon, 19 Jan 2026, Paul Ripke wrote:
Do we check for underscores somewhere in name resolution?
Yes.
I know that RFC 1035 disallows them from hostnames...
That's it.
I had a quick browse of our code and nothing obvious stood out.
I think: src/lib/libc/net/gethnamaddr.c: gethostbyname() > gethostbyname_r() -> gethostbyname_internal() -> nsdispatch() -> _dns_gethtbyname() -> getanswer() -> name_ok = res_hnok / maybe_ok() This works--see resolv.conf(5): # echo 'options no-check-names' >> /etc/resolv.conf -RVP
