services.nghttpx.backend-address-family

Specify address family of backend connections. If "auto" is given, both IPv4 and IPv6 are considered. If "IPv4" is given, only IPv4 address is considered. If "IPv6" is given, only IPv6 address is considered.

Please see https://nghttp2.org/documentation/nghttpx.1.html#cmdoption-nghttpx--backend-address-family.